51 results on '"Clarisse Ducruet"'
Search Results
2. Scalability and logic functionalities of TA-MRAMs.
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Ioan Lucian Prejbeanu, Ricardo C. Sousa, Bernard Dieny, Jean-Pierre Nozieres, S. Bandiera, Jérémy Alvarez-Herault, Q. Stainer, L. Lombard, Clarisse Ducruet, Y. Conraux, and Ken Mackay
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- 2013
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3. Reduced Thermal Variation of Perpendicular Magnetic Anisotropy in Magnetically Stiffened Dual-W Composite Storage Layer for Spin-Transfer-Torque Magnetic Random-Access Memory
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Ricardo C. Sousa, F. Fettar, Lucian Prejbeanu, Clarisse Ducruet, Stéphane Auffret, Bernard Dieny, I. Joumard, A. Chavent, Jyotirmoy Chatterjee, Laurent Vila, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Surfaces, Interfaces et Nanostructures (SIN ), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CROCUS Technology, and Surfaces, Interfaces et Nanostructures (NEEL - SIN)
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[PHYS]Physics [physics] ,Materials science ,Condensed matter physics ,Spintronics ,Composite number ,Spin-transfer torque ,General Physics and Astronomy ,chemistry.chemical_element ,Stiffness ,02 engineering and technology ,Tungsten ,021001 nanoscience & nanotechnology ,01 natural sciences ,Tunnel magnetoresistance ,Ferromagnetism ,chemistry ,0103 physical sciences ,medicine ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,medicine.symptom ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,010306 general physics ,0210 nano-technology ,Layer (electronics) ,ComputingMilieux_MISCELLANEOUS - Abstract
This article reports a type of magnetic tunnel junction (MTJ) with an expanded middle layer, for spin-transfer-torque magnetic random-access memory (STT-MRAM). This data-storage layer of the form Fe-Co-B/W/Co/W/Fe-Co-B sandwiches a ferromagnet with high exchange stiffness between two tungsten films, and thus is much less sensitive to temperature than that in a conventional MTJ. Such a storage layer is promising for spintronic memory that must operate across a wide range of temperatures, as in automobile applications.
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- 2019
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4. Evaluation of a new MgO barrier based on CoFeB/MgO/CoFeB structure for advanced MRAM applications
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T. Sedoykina, A. Orlov, Jeremy Pereira, Jérémy Alvarez-Hérault, C. Portemont, Clarisse Ducruet, E. Danilkin, and E. Smirnov
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010302 applied physics ,Magnetoresistive random-access memory ,Materials science ,Spintronics ,Nanotechnology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Engineering physics ,Atomic and Molecular Physics, and Optics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Non-volatile memory ,Tunnel magnetoresistance ,Sputtering ,0103 physical sciences ,Static random-access memory ,Electrical and Electronic Engineering ,0210 nano-technology ,Dram - Abstract
MRAM technology offers the opportunity to provide all the advantages of the most popular types of memory, such as DRAM, SRAM and FLASH with none of its disadvantages. Magnetic tunnel junctions (MTJs) based on CoFeB/MgO/CoFeB structures are very promising for future spintronics, especially in MRAM memory operation due to its high tunnel magnetoresistance (TMR) and reasonable range of resistance area product (RA). The deposition process of MgO barrier in such structures is one of the most difficult challenges to achieve good parameters of MTJs and it strongly affects on the barrier roughness, especially on the low RA region because of insufficient crystallization of thin MgO on an amorphous CoFeB. Ordinary MgO barrier creation takes a long time due to obligatory steps of Mg oxidation in different module that makes process complicated and provides a risk of CoFeB oxidation through Mg. It is shown that the new approach of barrier formation using in-situ MgO RF sputtering with Mg insertions and higher Ar partial pressure has very promising ratio of TMR vs RA which can be used in MTJs required for low "read" and "write" currents having a big delta between Rmin and Rmax in the most advanced MRAM applications.
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- 2017
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5. Tuning the Granular Contribution to Exchange Bias by Varying the Antiferromagnetic Material but Without Affecting the Ferromagnetic/Antiferromagnetic Interface
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L. Frangou, I. Joumard, K. Akmaldinov, Vincent Baltz, Bernard Dieny, Clarisse Ducruet, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and CROCUS Technology
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volume ,Materials science ,Spins ,Spintronics ,Condensed matter physics ,Context (language use) ,Physics and Astronomy(all) ,TA-MRAM ,Exchange bias ,Ferromagnetism ,exchange bias ,blocking temperature distribution ,interface ,Antiferromagnetism ,Thermal stability ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,Diffusion (business) - Abstract
International audience; The exchange bias properties of ferromagnetic/antiferromagnetic (F/AF) bilayers depend strongly on both the F and AF bulk properties, and the interfacial uncompensated AF spins that magnetically couple the F and the AF materials. Whether it is possible to adjust the bulk properties of the AF layer by changing the nature of the AF material but without affecting the interface is one of the challenges raised by the development of some spintronic devices. In this context, we engineered composite AF materials whose basic composition is: (FeMn/Pt/AF). These structures are made of FeMn and IrMn alloys with the insertion of a thin Pt diffusion/trap barrier to Mn in order to ensure as much as possible the integrity of the AF layer at the interface. Magnetic measurements evidenced that, by changing the nature of the AF material, it remains possible to tune the thermal stability of the AF grains without affecting much the interface.
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- 2015
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6. Noise study of magnetic field sensors based on magnetic tunnel junctions
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Myckael Mouchel, C. Baraduc, Amandine Bocheux, Jérémy Alvarez-Hérault, Clarisse Ducruet, K. Mackay, Ph. Sabon, Y. Conraux, I. L. Prejbeanu, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CROCUS Technology, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)
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010302 applied physics ,Physics ,History ,Infrasound ,Acoustics ,Low frequency ,01 natural sciences ,Noise (electronics) ,Computer Science Applications ,Education ,Magnetic field ,Low noise ,Amplitude ,0103 physical sciences ,[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det] ,Noise level ,Sensitivity (electronics) - Abstract
International audience; Low frequency noise has been studied for two types of magnetic field sensors based on magnetic tunnel junctions (MTJ). The first structure, composed of a few large MTJs, is designed for low noise applications; the second one, composed of hundreds of small MTJs, is designed for general purposes. At low frequency, both structures exhibit 1/f noise, but with very different amplitudes. The sensors for general purposes show a much higher noise level compared to the low-noise sensors. However, the sensitivity of the low noise sensors is much smaller compared to the other ones. Thus, the limit of detection, defined as the ratio of noise and sensitivity, turns out to be roughly the same for both technologies. Using the advantages of each sensor could help to design a sensor with an improved limit of detection.
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- 2017
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7. Enhanced annealing stability and perpendicular magnetic anisotropy in perpendicular magnetic tunnel junctions using W layer
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N. Perrissin, Jyotirmoy Chatterjee, Stéphane Auffret, Ricardo C. Sousa, Clarisse Ducruet, Bernard Dieny, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CROCUS Technology, ANR-13-NANO-0010,EXCALYB,Cellules MRAM sub-20nm et intégration CMOS de circuits hybrides(2013), ANR-10-LABX-0055,MINOS Lab,Minatec Novel Devices Scaling Laboratory(2010), and European Project: 669204,H2020,ERC-2014-ADG,MAGICAL(2015)
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010302 applied physics ,Materials science ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Annealing (metallurgy) ,Perpendicular magnetic anisotropy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Tunnel magnetoresistance ,Nuclear magnetic resonance ,0103 physical sciences ,Electrode ,Thermal ,Perpendicular ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Antiferromagnetism ,0210 nano-technology ,Anisotropy - Abstract
International audience; The magnetic properties of the perpendicular storage electrode (buffer/MgO/FeCoB/Cap) were studied as a function of annealing temperature by replacing Ta with W and W/Ta cap layers with variable thicknesses. W in the cap boosts up the annealing stability and increases the effective perpendicular anisotropy by 30% compared to the Ta cap. Correspondingly, an increase in the FeCoB critical thickness characterizing the transition from perpendicular to in-plane anisotropy was observed. Thicker W layer in the W(t)/Ta 1 nm cap layer makes the storage electrode highly robust against annealing up to 570 °C. The stiffening of the overall stack resulting from the W insertion due to its very high melting temperature seems to be the key mechanism behind the extremely high thermal robustness. The Gilbert damping constant of FeCoB with the W/Ta cap was found to be lower when compared with the Ta cap and stable with annealing. The evolution of the magnetic properties of bottom pinned perpendicular magnetic tunnel junctions (p-MTJ) stack with the W2/Ta1 nm cap layer shows back-end-of-line compatibility with increasing tunnel magnetoresistance up to the annealing temperature of 425 °C. The pMTJ thermal budget is limited by the synthetic antiferromagnetic hard layer which is stable up to 425 °C annealing temperature while the storage layer is stable up to 455 °C.
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- 2017
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8. High sensitivity magnetic field sensor for spatial applications
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Myckael Mouchel, C. Baraduc, Ioan Lucian Prejbeanu, Claude Cavoit, Philippe Sabon, Clarisse Ducruet, Amandine Bocheux, Romain Fons, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), CROCUS Technology, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
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010302 applied physics ,Materials science ,Magnetic energy ,Electromagnet ,business.industry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Magnetic flux ,law.invention ,Magnetic circuit ,Search coil ,Magnetic core ,Electromagnetic coil ,law ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Optoelectronics ,Magnetic pressure ,0210 nano-technology ,business - Abstract
International audience; A high sensitivity 1D magnetic field sensor is developed for spatial applications, in order to replace the heavy search-coils currently used. This new sensor combines a flux concentrator, biasing coils for field modulation and magnetic tunnel junctions. These three elements are fabricated and independently characterized. Finally, the expected performance of a sensor combining these three elements can be estimated.
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- 2016
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9. Correlation Between Perpendicular Anisotropy and Magnetoresistance in Magnetic Tunnel Junctions
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Bernard Dieny, C. Portemont, I Lucian Prejbeanu, Clarisse Ducruet, Bernard Rodmacq, and Lavinia Elena Nistor
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Materials science ,Magnetoresistance ,Condensed matter physics ,Perpendicular magnetic anisotropy ,chemistry.chemical_element ,Electronic, Optical and Magnetic Materials ,Magnetization ,Tunnel magnetoresistance ,Magnetic anisotropy ,chemistry ,Electrode ,Electrical and Electronic Engineering ,Platinum ,Cobalt - Abstract
The perpendicular magnetic anisotropy (PMA) of Pt/CoFe(B)/MgO bottom electrodes and the tunnel magnetoresistance (TMR) of CoFeB-based magnetic tunnel junctions (MTJ) have been analyzed as a function of Mg thickness for naturally oxidized barriers. Low PMA and TMR values are found for over-oxidized (small MgO thickness) and under-oxidized (large MgO thickness) barriers. When CoFe is used as bottom electrode, a strong correlation is observed between TMR and PMA variation as a function of MgO thickness with maxima in both quantities occurring for an MgO thickness around 1.2 nm. On the contrary, for CoFeB bottom electrodes, the sensitivity of PMA to MgO thickness is completely lost, as a probable consequence of boron diffusion towards the MgO interface.
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- 2010
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10. X-ray analysis of oxygen-induced perpendicular magnetic anisotropy in trilayers
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Giancarlo Panaccione, Stefania Pizzini, Stéphane Auffret, Lucien Lombard, Bernard Dieny, Bernard Rodmacq, Jan Vogel, Clarisse Ducruet, Aurelien Manchon, M. Hochstrasser, and Vojtech Uhlir
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Materials science ,Absorption spectroscopy ,Condensed matter physics ,Annealing (metallurgy) ,Magnetic circular dichroism ,02 engineering and technology ,Dichroism ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electron spectroscopy ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,Nuclear magnetic resonance ,X-ray photoelectron spectroscopy ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Anisotropy ,Spectroscopy - Abstract
X-ray spectroscopy measurements have been performed on a series of Pt/Co/AlOx trilayers to investigate the role of Co oxidation in the perpendicular magnetic anisotropy of the Co/AlOx interface. It is observed that high temperature annealing modifies the magnetic properties of the Co layer, inducing an enhancement of the perpendicular magnetic anisotropy. The microscopic structural properties are analyzed via X-ray Absorption Spectroscopy, X-ray Magnetic Circular Dichroism and X-ray Photoelectron Spectroscopy measurements. It is shown that annealing enhances the amount of interfacial oxide, which may be at the origin of a strong perpendicular magnetic anisotropy.
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- 2008
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11. Spin–Charge Conversion Phenomena in Germanium
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Jean-Philippe Attané, Serge Gambarelli, F. Rortais, Matthieu Jamet, Henri Jaffrès, Hanako Okuno, Julie Widiez, Stéphanie Pouget, C. Vergnaud, P. Laczkowski, Simón Oyarzún, Clarisse Ducruet, Juan-Carlos Rojas-Sánchez, Federico Bottegoni, Alain Marty, C. Beigné, J.-M. George, Laurent Vila, Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, Service Général des Rayons X (SGX ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ), Conception d’Architectures Moléculaires et Processus Electroniques (CAMPE), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), THALES [France]-Centre National de la Recherche Scientifique (CNRS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
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Spin pumping ,Materials science ,Spin polarization ,Condensed matter physics ,business.industry ,Doping ,General Physics and Astronomy ,chemistry.chemical_element ,Germanium ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Semiconductor ,Quantum spin Hall effect ,chemistry ,0103 physical sciences ,Spin Hall effect ,Condensed Matter::Strongly Correlated Electrons ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,010306 general physics ,0210 nano-technology ,Spin (physics) ,business ,ComputingMilieux_MISCELLANEOUS - Abstract
The spin–orbit coupling relating the electron spin and momentum allows for spin generation, detection and manipulation. It thus fulfils the three basic functions of the spin field-effect-transistor made of semiconductors. In this paper, we review our recent results on spin–charge conversion in bulk germanium and at the Ge(111) surface. We used the spin pumping technique to generate pure spin currents to be injected into bulk germanium and at the Fe/Ge(111) interface. The mechanism for spin–charge conversion in bulk germanium is the spin Hall effect and we could experimentally determine the spin Hall angle θSHE, i.e., the spin–charge conversion efficiency, in heavily doped n-type and p-type germanium. We found very small values at room temperature: θSHE ≈ (1–2) × 10−3 in n-Ge and θSHE ≈ (6–7) × 10−4 in p-Ge. Moreover, we pointed out the essential role of spin dependent scattering on ionized impurities in the spin Hall effect mechanism. We concluded that the spin Hall effect in bulk germanium is too weak to...
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- 2016
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12. Electrical spin injection in silicon and the role of defects
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F. Rortais, C. Vergnaud, Jean-Philippe Attané, Matthieu Jamet, Henri Jaffrès, Alain Marty, C. Beigné, Julie Widiez, Clarisse Ducruet, J.-M. George, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CROCUS Technology, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES-Centre National de la Recherche Scientifique (CNRS), ANR-13-BS10-0002,SiGeSPIN,Spintronique dans le silicium et le germanium(2013), and THALES [France]-Centre National de la Recherche Scientifique (CNRS)
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010302 applied physics ,Hanle effect ,Materials science ,Silicon ,Condensed matter physics ,Magnetoresistance ,chemistry.chemical_element ,Germanium ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Signal ,chemistry ,Ferromagnetism ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,0210 nano-technology ,Quantum tunnelling ,Spin-½ - Abstract
International audience; Three-terminal devices, where the same ferromagnetic electrode is used for electrical spin injection and detection, is a very easy and powerful tool to probe the spin properties in nonmagnetic materials. For instance, it has been intensively used to study spin injection and detection in silicon. However the interpretation of the magnetoresistance signals observed experimentally is still under debate. In particular, a controversy has been raised about the experimental spin signal which is orders of magnitude larger than the predicted value. Recently, Song et al. [Phys. Rev. Lett. 113, 047205 (2014)] proposed that the magnetoresistance signal measured using the Hanle effect in a three-terminal geometry is due to defects or impurities in the tunnel barrier separating the ferromagnetic electrode from the silicon channel. It has also been supported by the experimental work of Txoperena et al. [Phys. Rev. Lett. 113, 146601 (2014)]. In this study, we perform electrical spin injection/detection measurements using three-terminal devices in different silicon films and study the role of defects. For this purpose, we use the tunneling inelastic spectroscopy to measure the Hanle effect and control the presence of defects in the tunnel barrier. Contrary to previous reports, we demonstrate that defects have no significant contribution to the spin signal. From a comparison with capacitance-voltage measurements in n-doped germanium in which interface states contribute to the spin signal, we also conclude on the presence of interface states in silicon.
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- 2016
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13. Steady State and Dynamics of Joule Heating in Magnetic Tunnel Junctions Observed via the Temperature Dependence of RKKY Coupling
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C. Portemont, I. L. Prejbeanu, Antoine Chavent, Ricardo C. Sousa, Clarisse Ducruet, Laurent Vila, Jérémy Alvarez-Hérault, Bernard Dieny, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CROCUS Technology, and ANR-13-NANO-0010,EXCALYB,Cellules MRAM sub-20nm et intégration CMOS de circuits hybrides(2013)
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Coupling ,Magnetoresistive random-access memory ,Condensed Matter - Materials Science ,Materials science ,Steady state ,Condensed matter physics ,Magnetic moment ,Spintronics ,General Physics and Astronomy ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,02 engineering and technology ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,021001 nanoscience & nanotechnology ,01 natural sciences ,3. Good health ,Tunnel magnetoresistance ,0103 physical sciences ,Torque ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,010306 general physics ,0210 nano-technology ,Joule heating ,ComputingMilieux_MISCELLANEOUS - Abstract
Understanding quantitatively the heating dynamics in magnetic tunnel junctions (MTJ) submitted to current pulses is very important in the context of spin-transfer-torque magnetic random access memory development. Here we provide a method to probe the heating of MTJ using the RKKY coupling of a synthetic ferrimagnetic storage layer as a thermal sensor. The temperature increase versus applied bias voltage is measured thanks to the decrease of the spin-flop field with temperature. This method allows distinguishing spin transfer torque (STT) effects from the influence of temperature on the switching field. The heating dynamics is then studied in real-time by probing the conductance variation due to spin-flop rotation during heating. This approach provides a new method for measuring fast heating in spintronic devices, particularly magnetic random access memory (MRAM) using thermally assisted or spin transfer torque writing., Comment: 6 pages, 9 figures
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- 2016
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14. Controlled pulse shape cooling in planar TAS-STT-MRAM for improved writeability
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Jérémy Alvarez-Hérault, Laurent Vila, C. Portemont, A. Chavent, B. Dieny, C. Creuzet, Clarisse Ducruet, R. C. Sousa, and I. L. Prejbeanu
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Magnetoresistive random-access memory ,Nuclear magnetic resonance ,Materials science ,Condensed matter physics ,Phase (waves) ,Spin-transfer torque ,Antiferromagnetism ,Current (fluid) ,Pulse (physics) ,Voltage ,Magnetic field - Abstract
In field written thermally assisted (TAS) MRAM, the storage layer is pinned with an antiferromag-netic layer. The writing of TAS-MRAM consists of heating the storage layer above the blocking temperature of the antiferromagnet using an injected current pulse through the tunnel barrier. This pulse can be used to assist the writing either combined to an external magnetic field or to a spin transfer torque (STT) [1] effect coming from the spin polarized current flow. After setting the storage layer direction during the write step, the current pulse is removed, pinning the storage layer in the set direction. The actual temperature decay occurs in a timescale of few tens of nanoseconds [2]. STT is efficient while the current is flowing through the junction but disappears during cooling, once the heating pulse is removed. This assumption is valid if the temperature gradients across the barrier, giving rise to spin accumulation of thermal origin are negligible. In these conditions, when the temperature is above or close to the blocking temperature of the antiferromagnetic layer pinning the storage layer, the written state might be thermally unstable. In this paper, we have investigated the possibility of controlling the temperature decay, so that the spin polarized current and temperature decay at the same rate. We show that there is an improvement in writing reproducibility using a linear transition at the end of the current pulse during the cooling phase. This is especially evident in cases where STT influence on the field writing is more significant. The write error rate dependence with the voltage transition duration was measured, and we find an optimum value for a 70ns transition, corresponding to a linear pulse amplitude decay of 18mV/ns.
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- 2015
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15. Correlation Between Disordered Magnetic Phases in Ferromagnetic/Antiferromagnetic Thin Films and Device-to-Device Variability of Exchange Bias in Spintronic Applications
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L. Frangou, I. Joumard, Vincent Baltz, K. Akmaldinov, Jeremy Pereira, Clarisse Ducruet, C. Portemont, Jérémy Alvarez-Hérault, Bernard Dieny, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and CROCUS Technology
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[PHYS]Physics [physics] ,Materials science ,Spintronics ,Condensed matter physics ,Device to device ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Magnetic hysteresis ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,Nanolithography ,Exchange bias ,Ferromagnetism ,0103 physical sciences ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Thin film ,010306 general physics ,0210 nano-technology - Abstract
International audience; Spintronic applications rely on ferromagnetic/antiferromagnetic exchange biased bilayers. In this study, we show whether and how disordered magnetic phases, which exhibit low freezing temperatures and are located in the ferromagnetic/antiferromagnetic thin film, affect the device-to-device variability of exchange bias in magnetic applications once the film is nanofabricated.
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- 2015
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16. Modulation of spin transfer torque amplitude in double barrier magnetic tunnel junctions
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Claire Baraduc, Bernard Dieny, Mairbek Chshiev, Laurent Vila, Clarisse Ducruet, P.-Y. Clement, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CROCUS Technology, and European Project: 246942,EC:FP7:ERC,ERC-2009-AdG,HYMAGINE(2010)
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Physics ,[PHYS]Physics [physics] ,Magnetoresistive random-access memory ,Angular momentum ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Magnetoresistance ,Spin-transfer torque ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Bias-Voltage ,Tunnel effect ,Magnetization ,Modulation ,0103 physical sciences ,Torque ,010306 general physics ,0210 nano-technology ,Spin-½ - Abstract
International audience; Magnetization switching induced by spin transfer torque is used to write magnetic memories (Magnetic Random Access Memory, MRAM) but can be detrimental to the reading process. It would be quite convenient therefore to modulate the efficiency of spin transfer torque. A solution is adding an extra degree of freedom by using double barrier magnetic tunnel junctions with two spin-polarizers, with controllable relative magnetic alignment. We demonstrate, for these structures, that the amplitude of in-plane spin transfer torque on the middle free layer can be efficiently tuned via the magnetic configuration of the electrodes. Using the proposed design could thus pave the way towards more reliable read/write schemes for MRAM. Moreover, our results suggest an intriguing effect associated with the out-of-plane (field-like) spin transfer torque, which has to be further investigated. (C) 2015 AIP Publishing LLC.
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- 2015
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17. Ferromagnetic tunnel contacts to graphene: Contact resistance and spin signal
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Marie-Blandine Martin, Laurent Vila, Matthieu Jamet, Alain Marty, Jean-Philippe Attané, Abdelmadjid Anane, Stéphane Auffret, C. Vergnaud, Cyrile Deranlot, Pierre Seneor, Clarisse Ducruet, P. Laczkowski, L. Notin, Albert Fert, M. Cubukcu, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11), CROCUS Technology, and THALES [France]-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Materials science ,business.industry ,Graphene ,Contact resistance ,Precession ,General Physics and Astronomy ,Transport ,02 engineering and technology ,Chemical vapor deposition ,Sputter deposition ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Tunnel magnetoresistance ,Surface coating ,Nuclear magnetic resonance ,Transition metal ,Sputtering ,law ,0103 physical sciences ,Optoelectronics ,010306 general physics ,0210 nano-technology ,business - Abstract
International audience; We report spin transport in CVD graphene-based lateral spin valves using different magnetic contacts. We compared the spin signal amplitude measured on devices where the cobalt layer is directly in contact with the graphene to the one obtained using tunnel contacts. Although a sizeable spin signal (up to similar to 2 Omega) is obtained with direct contacts, the signal is strongly enhanced (similar to 400 Omega) by inserting a tunnel barrier. In addition, we studied the resistance-area product (R. A) of a variety of contacts on CVD graphene. In particular, we compared the R. A products of alumina and magnesium oxide tunnel barriers grown by sputtering deposition of aluminum or magnesium and subsequent natural oxidation under pure oxygen atmosphere or by plasma. When using an alumina tunnel barrier on CVD graphene, the R. A product is high and exhibits a large dispersion. This dispersion can be highly reduced by using a magnesium oxide tunnel barrier, as for the R. A value. This study gives insight in the material quest for reproducible and efficient spin injection in CVD graphene. (C) 2015 AIP Publishing LLC.
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- 2015
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18. Influence of cooling rate in planar thermally assisted magnetic random access memory: Improved writeability due to spin-transfer-torque influence
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C. Creuzet, Bernard Dieny, Ioan Lucian Prejbeanu, Antoine Chavent, Ricardo C. Sousa, Laurent Vila, Jérémy Alvarez-Hérault, C. Portemont, Clarisse Ducruet, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CROCUS Technology, and ANR-13-NANO-0010,EXCALYB,Cellules MRAM sub-20nm et intégration CMOS de circuits hybrides(2013)
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Coupling ,[PHYS]Physics [physics] ,RKKY interaction ,Materials science ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Spin-transfer torque ,Geomagnetic reversal ,Magnetic field ,Magnetization ,Tunnel-Junctions ,Ferrimagnetism ,Electrode ,Temperature-Dependence - Abstract
International audience; This paper investigates the effect of a controlled cooling rate on magnetic field reversal assisted by spin transfer torque (STT) in thermally assisted magnetic random access memory. By using a gradual linear decrease of the voltage at the end of the write pulse, the STT decays more slowly or at least at the same rate as the temperature. This condition is necessary to make sure that the storage layer magnetization remains in the desired written direction during cooling of the cell. The influence of the write current pulse decay rate was investigated on two exchange biased synthetic ferrimagnet (SyF) electrodes. For a NiFe based electrode, a significant improvement in writing reproducibility was observed using a gradual linear voltage transition. The write error rate decreases by a factor of 10 when increasing the write pulse fall-time from similar to 3 ns to 70 ns. For comparison, a second CoFe/NiFe based electrode was also reversed by magnetic field assisted by STT. In this case, no difference between sharp and linear write pulse fall shape was observed. We attribute this observation to the higher thermal stability of the CoFe/NiFe electrode during cooling. In real-time measurements of the magnetization reversal, it was found that Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling in the SyF electrode vanishes for the highest pulse voltages that were used due to the high temperature reached during write. As a result, during the cooling phase, the final state is reached through a spin-flop transition of the SyF storage layer. (C) 2015 AIP Publishing LLC.
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- 2015
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19. Mixing antiferromagnets to tune NiFe-[IrMn/FeMn] interfacial spin-glasses, grains thermal stability, and related exchange bias properties
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K. Akmaldinov, I. Joumard, I. L. Prejbeanu, B. Dieny, C. Portemont, Clarisse Ducruet, Vincent Baltz, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and CROCUS Technology
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Materials science ,Spin glass ,Spintronics ,Condensed matter physics ,Magnetism ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Exchange bias ,Ferromagnetism ,0103 physical sciences ,Antiferromagnetism ,Thermal stability ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,010306 general physics ,0210 nano-technology - Abstract
International audience; Spintronics devices and in particular thermally assisted magnetic random access memories require a wide range of ferromagnetic/antiferromagnetic (F/AF) exchange bias (EB) properties and subsequently of AF materials to fulfil diverse functionality requirements for the reference and storage. For the reference layer, large EB energies and high blocking temperature (T B) are required. In contrast, for the storage layer, mostly moderate T B are needed. One of the present issues is to find a storage layer with properties intermediate between those of IrMn and FeMn and in particular: (i) with a T B larger than FeMn for better stability at rest-T but lower than IrMn to reduce power consumption at write-T and (ii) with improved magnetic interfacial quality, i.e., with reduced interfacial glassy character for lower properties dispersions. To address this issue, the EB properties of F/AF based stacks were studied for various mixed [IrMn/FeMn] AFs. In addition to EB loop shifts, the F/AF magnetic interfacial qualities and the AF grains thermal stability are probed via measurements of the low-and high-temperature contributions to the T B distributions, respectively. A tuning of the above three parameters is observed when evolving from IrMn to FeMn via [IrMn/FeMn] repetitions.
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- 2014
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20. Double barrier magnetic tunnel junctions with write/read mode select layer
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C. Baraduc, Mairbek Chshiev, Clarisse Ducruet, Laurent Vila, B. Dieny, P.-Y. Clement, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and CROCUS Technology
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Materials science ,business.industry ,High voltage ,Magnetic field ,Tunnel magnetoresistance ,Magnetization ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Electronic engineering ,Optoelectronics ,business ,Current density ,Versa ,Antiparallel (electronics) ,Voltage - Abstract
International audience; In this study, special STT-RAM were designed, built and tested, allowing to read and write at similar voltages. This is achieved by maximizing the Spin-Transfer-Torque (STT) efficiency on the storage layer magnetization during write and minimizing it during read. In order to achieve this STT tuning, double barrier magnetic tunnel junctions were prepared wherein the storage layer is sandwiched between two polarizing layers. Each polarizing layer is separated from the storage layer by a tunnel barrier. The magnetization of one of the polarizing layer is always pinned in a fixed direction whereas the other one, called mode select layer, can be switched parallel or antiparallel to the first one depending whether the magnetic tunnel junction (MTJ) is in read or respectively write mode. In the parallel configuration of the polarizing layers, the STT efficiency is minimized allowing to read at relatively high voltage leading to fast readout without risk of write disturb during read. In the antiparallel configuration of the polarizing layer, the STT efficiency is maximized allowing writing at lower current density. In this system, the magnetization of the storage layer is switched by STT whereas the magnetization of the mode select layer is switched by field. Switching from read mode to write mode and vice versa is achieved by sharing a single pulse of magnetic field for all bits of the same word.
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- 2014
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21. FeMn Exchange Biased Storage Layer for Thermally Assisted MRAM
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Ricardo Sousa, Clarisse Ducruet, Marie Therese Delaye, C. Portemont, Christian Papusoi, Bernard Dieny, Jeremy Herault, Jean-Pierre Nozieres, Ken Mackay, Erwan Gapihan, and I Lucien Prejbeanu
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Magnetoresistive random-access memory ,Materials science ,Diffusion barrier ,Condensed matter physics ,Annealing (metallurgy) ,Electrical and Electronic Engineering ,Pulsed power ,Coercivity ,Magnetic hysteresis ,Current density ,Electronic, Optical and Magnetic Materials ,Power density - Abstract
Thermally assisted MRAM cells with FeMn exchange biased storage layers were successfully written using 50 ns current pulses with write power densities below 10 mW/?m2 and current densities below 1.3 ×10 6 A/cm2. These low power density values were achieved without using thermal barriers to confine the heat in the cell. Introducing thermal barriers would even further lower the write power density by increasing the heating efficiency. The storage layer coercivity increased upon anneal at 340 C. This could be related to manganese diffusion or to a texture incompatibility between the CoFe and the FeMn antiferromagnetic layer, a problem which can be fixed by insertion of appropriate diffusion barrier or texture control layer. Successful writing was observed for repeated write attempts with heating pulse power densities in the 7-12.5 mW/?m2 range.
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- 2010
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22. Modulating spin transfer torque switching dynamics with two orthogonal spin-polarizers by varying the cell aspect ratio
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Laurent Vila, M. Marins de Castro, Thibaut Devolder, R. C. Sousa, B. Dieny, Liliana D. Buda-Prejbeanu, Clarisse Ducruet, I. L. Prejbeanu, B. Lacoste, S. Auffret, Ursula Ebels, B. Rodmacq, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), IEF, Université Paris-Sud - Paris 11 (UP11), and CROCUS Technology
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[PHYS]Physics [physics] ,Materials science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed matter physics ,Spin-transfer torque ,FOS: Physical sciences ,02 engineering and technology ,Polarizer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Aspect ratio (image) ,Electronic, Optical and Magnetic Materials ,law.invention ,Tunnel magnetoresistance ,Magnetization ,law ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Perpendicular ,010306 general physics ,0210 nano-technology ,Anisotropy ,ComputingMilieux_MISCELLANEOUS ,Coherence (physics) - Abstract
We study in-plane magnetic tunnel junctions with additional perpendicular polarizer for subnanosecond-current-induced switching memories. The spin-transfer-torque switching dynamics was studied as a function of the cell aspect ratio both experimentally and by numerical simulations using the macrospin model. We show that the anisotropy field plays a significant role in the dynamics, along with the relative amplitude of the two spin-torque contributions. This was confirmed by micromagnetic simulations. Real-time measurements of the reversal were performed with samples of low and high aspect ratio. For low aspect ratios, a precessional motion of the magnetization was observed and the effect of temperature on the precession coherence was studied. For high aspect ratios, we observed magnetization reversals in less than 1 ns for high enough current densities, the final state being controlled by the current direction in the magnetic tunnel junction cell., Comment: 6 pages, 7 figures
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- 2014
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23. MRAM concepts for sub-nanosecond precessional switching and sub-20nm cell scaling
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M. Marins de Castro, Sébastien Bandiera, S. Auffret, R. C. Sousa, B. Dieny, L. San-Emeterio-Alvarez, I. L. Prejbeanu, Lavinia Elena Nistor, Ursula Ebels, B. Rodmacq, Laurent Vila, B. Lacoste, and Clarisse Ducruet
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Magnetoresistive random-access memory ,Materials science ,Condensed matter physics ,business.industry ,Spin-transfer torque ,Nanosecond ,Polarizer ,7. Clean energy ,01 natural sciences ,law.invention ,Tunnel magnetoresistance ,Tunnel junction ,law ,0103 physical sciences ,Perpendicular ,Optoelectronics ,010306 general physics ,business ,Nanopillar - Abstract
This work reports on advances in MRAM cells aiming at sub-nanosecond switching and for sub-20nm technology nodes. Ultrafast precessional spin-transfer switching in elliptical magnetic tunnel junction nanopillars is possible to obtain in samples integrating a perpendicular polarizer and a tunnel junction with in-plane magnetized electrodes. We show that spin transfer torque (STT) switching in less than 500ps can be achieved in these structures with corresponding write energy less than 100fJ. For high density integration and possibly sub-20nm diameter cells the use of a thermally assisted concept for perpendicular anisotropy cells, where the intrinsic heating is used to simultaneously achieve high thermal stability and low current switching.
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- 2013
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24. Scalability and logic functionalities of TA-MRAMs
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K. Mackay, I. L. Prejbeanu, R. C. Sousa, Sébastien Bandiera, Jérémy Alvarez-Hérault, Clarisse Ducruet, Quentin Stainer, Bernard Dieny, Y. Conraux, Lucien Lombard, and J.-P Nozieres
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Magnetoresistive random-access memory ,Hardware_MEMORYSTRUCTURES ,Materials science ,Induced anisotropy ,Perpendicular magnetic anisotropy ,business.industry ,Electrical engineering ,Magnetic tunnelling ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Engineering physics ,Computer Science::Hardware Architecture ,Hardware_GENERAL ,Power consumption ,Scalability ,business ,AND gate - Abstract
This paper describes the working principle of thermally assisted MRAM extending the downsize scalability of MRAM and introducing new functionalities particularly useful for security applications. Ultimately, STT switching assisted by thermally induced anisotropy reorientation can be used in MTJ with perpendicular magnetic anisotropy to obtain ultimate downsize scalability with reduced power consumption.
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- 2013
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25. Influence of a Ta spacer on the magnetic and transport properties of perpendicular magnetic tunnel junctions
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Bernard Dieny, Clarisse Ducruet, Léa Cuchet, Bernard Rodmacq, Stéphane Auffret, Ricardo C. Sousa, SPINtronique et TEchnologie des Composants (SPINTEC), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), ANR-10-NANO-0013,PATHOS,Matériaux à Anisotropie Perpendiculaire pour cellules Mémoire Magnétiques Non-volatiles Haute-densité(2010), European Project: 246942,EC:FP7:ERC,ERC-2009-AdG,HYMAGINE(2010), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
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010302 applied physics ,[PHYS]Physics [physics] ,Materials science ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Tantalum ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Magnetization ,Magnetic anisotropy ,Tunnel magnetoresistance ,Condensed Matter::Materials Science ,Nuclear magnetic resonance ,chemistry ,Condensed Matter::Superconductivity ,0103 physical sciences ,Electrode ,Perpendicular ,Coupling (piping) ,0210 nano-technology ,Layer (electronics) - Abstract
International audience; Ultrathin Ta layers were inserted in the bottom hard (Co/Pt)/Ta/CoFeB/MgO magnetic electrode of perpendicular magnetic tunnel junctions. The magnetization of the top part of this electrode abruptly falls in-plane when the Ta thickness exceeds 0.45 nm. This results from the balance between the various energy terms acting on this layer (exchange-like coupling through Ta, demagnetizing energy, and perpendicular anisotropy at the CoFeB/MgO interface). For small Ta thicknesses, this insertion leads to a strong improvement of the tunnel magnetoresistance, as long as the magnetization of all layers remains perpendicular-to-plane.
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- 2013
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26. Spin Pumping and Inverse Spin Hall Effect in Germanium
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M. Cubukcu, A. Jain, Serge Gambarelli, J.-M. George, Henri Jaffrès, Emmanuel Augendre, Clarisse Ducruet, Matthieu Jamet, Jean-Philippe Attané, C. Portemont, G. Desfonds, C. Vergnaud, Alain Marty, A. Barski, Juan-Carlos Rojas-Sánchez, and Laurent Vila
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Spin pumping ,Condensed Matter - Materials Science ,Materials science ,Magnetoresistance ,Condensed matter physics ,Electromotive force ,Condensed Matter - Mesoscale and Nanoscale Physics ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Condensed Matter Physics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Ferromagnetic resonance ,Electronic, Optical and Magnetic Materials ,Tunnel magnetoresistance ,Condensed Matter::Materials Science ,Hall effect ,Condensed Matter::Superconductivity ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Spin Hall effect ,Quantum tunnelling - Abstract
We have measured the inverse spin Hall effect (ISHE) in \textit{n}-Ge at room temperature. The spin current in germanium was generated by spin pumping from a CoFeB/MgO magnetic tunnel junction in order to prevent the impedance mismatch issue. A clear electromotive force was measured in Ge at the ferromagnetic resonance of CoFeB. The same study was then carried out on several test samples, in particular we have investigated the influence of the MgO tunnel barrier and sample annealing on the ISHE signal. First, the reference CoFeB/MgO bilayer grown on SiO$_{2}$ exhibits a clear electromotive force due to anisotropic magnetoresistance and anomalous Hall effect which is dominated by an asymmetric contribution with respect to the resonance field. We also found that the MgO tunnel barrier is essential to observe ISHE in Ge and that sample annealing systematically lead to an increase of the signal. We propose a theoretical model based on the presence of localized states at the interface between the MgO tunnel barrier and Ge to account for these observations. Finally, all of our results are fully consistent with the observation of ISHE in heavily doped $n$-Ge and we could estimate the spin Hall angle at room temperature to be $\approx$0.001., Comment: 34 pages, 14 figures
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- 2013
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27. Spin transport inp-type germanium
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F. Rortais, Simón Oyarzún, Juan-Carlos Rojas-Sánchez, C. Vergnaud, J.-M. George, P. Laczkowski, Serge Gambarelli, Federico Bottegoni, Clarisse Ducruet, Matthieu Jamet, Franco Ciccacci, Laurent Vila, Henri Jaffrès, Alberto Ferrari, Jean-Philippe Attané, Julie Widiez, Alain Marty, C. Beigné, Nicolas Reyren, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Politecnico di Milano [Milan] (POLIMI), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES [France]-Centre National de la Recherche Scientifique (CNRS), CROCUS Technology, Reconnaissance Ionique et Chimie de Coordination (RICC), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), ANR-13-BS10-0002,SiGeSPIN,Spintronique dans le silicium et le germanium(2013), Centre National de la Recherche Scientifique (CNRS)-THALES, Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
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Hanle effect ,Spin pumping ,Spintronics ,Spin polarization ,Condensed matter physics ,Chemistry ,02 engineering and technology ,Zero field splitting ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,7. Clean energy ,Spin wave ,0103 physical sciences ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Spin Hall effect ,Condensed Matter::Strongly Correlated Electrons ,General Materials Science ,Quantum spin liquid ,010306 general physics ,0210 nano-technology ,ComputingMilieux_MISCELLANEOUS - Abstract
We report on the spin transport properties in p-doped germanium (Ge-p) using low temperature magnetoresistance measurements, electrical spin injection from a ferromagnetic metal and the spin pumping-inverse spin Hall effect method. Electrical spin injection is carried out using three-terminal measurements and the Hanle effect. In the 2-20 K temperature range, weak antilocalization and the Hanle effect provide the same spin lifetime in the germanium valence band (≈1 ps) in agreement with predicted values and previous optical measurements. These results, combined with dynamical spin injection by spin pumping and the inverse spin Hall effect, demonstrate successful spin accumulation in Ge. We also estimate the spin Hall angle θ(SHE) in Ge-p (6-7 x 10(-4) at room temperature, pointing out the essential role of ionized impurities in spin dependent scattering.
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- 2016
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28. Sub-Nanosecond Precessional Switching in a MRAM Cell with a Perpendicular Polarizer
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M. Marins de Castro, A. Chavent, B. Dieny, Clarisse Ducruet, Ursula Ebels, A. Mejdoubi, B. Lacoste, Laurent Vila, S. Auffret, B. Rodmacq, Thibaut Devolder, R. C. Sousa, Liliana D. Buda-Prejbeanu, and I. L. Prjbeanu
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Physics ,Magnetoresistive random-access memory ,Condensed matter physics ,business.industry ,02 engineering and technology ,Polarizer ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,01 natural sciences ,020202 computer hardware & architecture ,law.invention ,Tunnel magnetoresistance ,law ,Tunnel junction ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Perpendicular ,Optoelectronics ,Electrical measurements ,010306 general physics ,business ,Ultrashort pulse ,Nanopillar - Abstract
This work reports sub-nanosecond precessional spin-transfer switching in elliptical magnetic tunnel junction nanopillars. This result is obtained in samples integrating a perpendicular polarizer and a tunnel junction with in-plane magnetized electrodes. We have performed statistics on time-resolved electrical measurements showing oscillations of the switching probability as a function of write voltage pulse width. This behavior is characteristic of the free layer precessional motion induced by the perpendicular polarizer. Ultrafast STT switching in less than 300ps could be achieved in these structures with corresponding write energy less than 100fJ.
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- 2012
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29. Crossover from spin accumulation into interface states to spin injection in the germanium conduction band
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J. Peiro, J. C. Le Breton, Matthieu Jamet, Emmanuel Augendre, Pascale Bayle-Guillemaud, A. Barski, Laurent Vila, Eric Prestat, Juan-Carlos Rojas-Sánchez, Vincent Baltz, M. Cubukcu, Henri Jaffrès, G. Desfonds, S. Gambarelli, Clarisse Ducruet, Jean-Philippe Attané, C. Portemont, J.-M. George, L. Louahadj, A. Jain, C. Vergnaud, Nanostructures et Magnétisme (NM), Service de Physique des Matériaux et Microstructures (SP2M - UMR 9002), Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut Nanosciences et Cryogénie (INAC), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CROCUS Technology, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Magnetic Resonance (RM ), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), THALES [France]-Centre National de la Recherche Scientifique (CNRS), and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
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010302 applied physics ,Spin pumping ,Condensed Matter - Materials Science ,Materials science ,Condensed matter physics ,Spin polarization ,Spintronics ,Condensed Matter - Mesoscale and Nanoscale Physics ,General Physics and Astronomy ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,02 engineering and technology ,Zero field splitting ,021001 nanoscience & nanotechnology ,01 natural sciences ,Tunnel magnetoresistance ,Spin wave ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Spin Hall effect ,Spin diffusion ,Condensed Matter::Strongly Correlated Electrons ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,0210 nano-technology - Abstract
Electrical spin injection into semiconductors paves the way for exploring new phenomena in the area of spin physics and new generations of spintronic devices. However the exact role of interface states in spin injection mechanism from a magnetic tunnel junction into a semiconductor is still under debate. In this letter, we demonstrate a clear transition from spin accumulation into interface states to spin injection in the conduction band of $n$-Ge. We observe spin signal amplification at low temperature due to spin accumulation into interface states followed by a clear transition towards spin injection in the conduction band from 200 K up to room temperature. In this regime, the spin signal is reduced down to a value compatible with spin diffusion model. More interestingly, we demonstrate in this regime a significant modulation of the spin signal by spin pumping generated by ferromagnetic resonance and also by applying a back-gate voltage which are clear manifestations of spin current and accumulation in the germanium conduction band., 5 pages, 4 figures
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- 2012
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30. Diffusive model of current-in-plane-tunneling in double magnetic tunnel junctions
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Claire Baraduc, Clarisse Ducruet, Bernard Dieny, P.-Y. Clement, Mairbek Chshiev, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CROCUS Technology, HYMAGINE (246942), and European Project: 246942,EC:FP7:ERC,ERC-2009-AdG,HYMAGINE(2010)
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Materials science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Physics and Astronomy (miscellaneous) ,Magnetoresistance ,Condensed matter physics ,FOS: Physical sciences ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Double barrier ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,01 natural sciences ,Measure (mathematics) ,Condensed Matter - Other Condensed Matter ,In plane ,Condensed Matter::Superconductivity ,0103 physical sciences ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Current (fluid) ,Diffusion (business) ,010306 general physics ,0210 nano-technology ,Quantum tunnelling ,[PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall] ,Other Condensed Matter (cond-mat.other) - Abstract
We propose a model that describes current-in-plane tunneling transport in double barrier magnetic tunnel junctions in diffusive regime. Our study shows that specific features appear in double junctions that are described by introducing two typical length scales. The model may be used to measure the magnetoresistance and the resistance area product of both barriers in unpatterned stacks of double barrier magnetic tunnel junctions., Comment: 4 pages, 3 figures
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- 2012
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31. Heating asymmetry induced by tunneling current flow in magnetic tunnel junctions
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Clarisse Ducruet, R. C. Sousa, B. Dieny, C. Portemont, Y. Dahmane, Laurent Vila, K. Mackay, J.-P. Nozieres, Erwan Gapihan, Ioan Lucian Prejbeanu, J. Herault, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service de Physique des Matériaux et Microstructures (SP2M - UMR 9002), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CROCUS Technology, ANR-07-NANO-052-02 Project, and European Project: 246942,EC:FP7:ERC,ERC-2009-AdG,HYMAGINE(2010)
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010302 applied physics ,[PHYS]Physics [physics] ,Materials science ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Fermi level ,02 engineering and technology ,Dissipation ,021001 nanoscience & nanotechnology ,01 natural sciences ,symbols.namesake ,Tunnel magnetoresistance ,Exchange bias ,Ballistic conduction ,0103 physical sciences ,symbols ,Current (fluid) ,0210 nano-technology ,Joule heating ,Quantum tunnelling - Abstract
International audience; In this work, exchange bias was used as a probe to characterise the temperature profile induced by the inelastic relaxation of electrons tunnelling across a MgO barrier. Thermally assisted magnetic random access memory (TA-MRAM) cells comprising a magnetic tunnel junction (MTJ) with a reference pinned layer and a FeMn exchange biased storage layer were used. The pinning direction of the ferromagnetic storage layer is reversed when heated above the blocking temperature of the antiferromagnetic layer (FeMn). The power density required to reach this blocking temperature in the FeMn layer depends on the current polarity, indicating that the heat source term associated with the current flowing through the barrier depends itself on the current direction in contrast to simple Joule heating. This effect is due to the mechanism of energy dissipation in tunnelling. The tunnelling itself is ballistic i.e., without dissipation. However, after tunnelling, the hot electrons very quickly relax to the Fermi energy thereby loosing their excess energy in the receiving electrode. Therefore, the heat is essentially generated on one side of the barrier so that the whole profile of temperature throughout the pillar depends on the current direction. Full 3D thermal simulations also confirmed the temperature profile asymmetry. The proper choice of heating current direction (i.e., voltage polarity applied to the MTJ) can yield a reduction of about 10% in the heating power density required to enable writing in thermally assisted MRAM cells.
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- 2012
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32. Extended scalability and functionalities of MRAM based on thermally-assisted writing
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Stéphane Auffret, C. Portemont, Ricardo Sousa, Bertrand Cambou, S. Bandiera, J.P. Nozieres, J. Herault, Bernard Dieny, Ioan Lucian Prejbeanu, Clarisse Ducruet, Bernard Rodmacq, K. Mackay, Erwan Gapihan, and M. Castro Souza
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010302 applied physics ,Magnetoresistive random-access memory ,Hardware_MEMORYSTRUCTURES ,Memory hierarchy ,business.industry ,Computer science ,Electrical engineering ,02 engineering and technology ,Avionics ,021001 nanoscience & nanotechnology ,01 natural sciences ,Microcontroller ,Hardware_GENERAL ,Embedded system ,0103 physical sciences ,Scalability ,Node (circuits) ,0210 nano-technology ,business ,Dram ,Electronic circuit - Abstract
MRAM are already used in low density applications such as microcontrollers or for spatial/avionics applications where they benefit from their radiation hardness. Thermally assisted writing allows extending the downsize scalability of both FIMS and STT-MRAM below the 20nm node. Within a few years, MRAM can play an important role in the memory hierarchy of electronic circuits. They may be first used as DRAM replacement below the 20nm node and in a second step even closer the logic units (Fig.10).
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- 2011
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33. Spin transfer torque switching assisted by thermally induced anisotropy reorientation in perpendicular magnetic tunnel junctions
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I. L. Prejbeanu, S. Auffret, M. Marins de Castro, S. Bandiera, R. C. Sousa, Clarisse Ducruet, Bernard Dieny, C. Portemont, B. Rodmacq, and Laurent Vila
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010302 applied physics ,Magnetoresistive random-access memory ,Materials science ,Physics and Astronomy (miscellaneous) ,Spin polarization ,Condensed matter physics ,Spin-transfer torque ,02 engineering and technology ,021001 nanoscience & nanotechnology ,7. Clean energy ,01 natural sciences ,Tunnel magnetoresistance ,Magnetization ,Magnetic anisotropy ,Spin wave ,0103 physical sciences ,Perpendicular ,0210 nano-technology - Abstract
A method to switch the magnetization of the free layer in magnetic tunnel junctions with perpendicular anisotropy is demonstrated. It consists in assisting the spin transfer switching of the magnetization by a thermally induced reorientation of the free layer magnetic anisotropy from out-of-plane to in-plane. The junction temperature increase is due to the Joule dissipation around the tunnel barrier produced by the same pulse of current which generates the spin transfer torque. This magnetic reorientation allows the spin transfer torque efficiency to be maximal since the spin polarization of the current is perpendicular to the magnetization of the free layer. Such a thermally assisted switching allows designing highly down-size scalable magnetoresistive random access memory cells with improved write efficiency.
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- 2011
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34. Spintronic Devices for Memory and Logic Applications
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G. Prenat, Ursula Ebels, Bernard Dieny, D. Houssameddine, M.-C. Cyrille, J. Hérault, Bernard Rodmacq, Ricardo Sousa, L. Prejbeanu-Buda, Clarisse Ducruet, Cristian Papusoi, B. Delaet, Olivier Redon, Stéphane Auffret, J.-P. Nozieres, and Lucian Prejbeanu
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Magnetoresistive random-access memory ,Hardware_MEMORYSTRUCTURES ,Spintronics ,Computer science ,business.industry ,Magnetism ,Nanotechnology ,Polarizer ,law.invention ,Computer Science::Hardware Architecture ,Magnetization ,Tunnel magnetoresistance ,CMOS ,Hardware_GENERAL ,law ,Optoelectronics ,Electronics ,Hardware_ARITHMETICANDLOGICSTRUCTURES ,business - Abstract
Publisher Summary Spinelectronics is a very rapidly expanding area of research and development that merges magnetism and electronics. It aims at taking advantage of the quantum characteristic of the electrons that is its spin to create new functionalities and new devices. Spintronic devices comprise magnetic layers that serve as spin polarizers or analyzers separated by non-magnetic layers through which the spin-polarized electrons are transmitted. It provides a new way to manipulate the magnetization of magnetic nanostructures by a spin-polarized current. Spinelectronics has found applications in hard disk drives and more recently in nonvolatile standalone memories, such as magnetic random access memory (MRAM). Furthermore, in addition to MRAMs, hybrid complementary metaloxide-semiconductor (CMOS)/magnetic technology can yield a totally new approach in the way electronic devices are designed. The hybrid CMOS/magnetic tunnel junction (MTJ) technology is progressing fast and gradually becomes more and more reliable. This hybrid CMOS/ magnetic technology has very important application in the field of lowpower, reprogrammable, and non-volatile logic.
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- 2011
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35. Comparison of Synthetic Antiferromagnets and Hard Ferromagnets as Reference Layer in Magnetic Tunnel Junctions With Perpendicular Magnetic Anisotropy
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B. Dieny, Vincent Baltz, C. Portemont, Stéphane Auffret, Sébastien Bandiera, Y. Dahmane, Ioan Lucian Prejbeanu, Clarisse Ducruet, R. C. Sousa, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and CROCUS Technology
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010302 applied physics ,Materials science ,Condensed matter physics ,Perpendicular magnetic anisotropy ,Nanostructured materials ,media_common.quotation_subject ,Magnetic tunnelling ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Magnetic hysteresis ,01 natural sciences ,Asymmetry ,Electronic, Optical and Magnetic Materials ,Dipole ,Ferromagnetism ,0103 physical sciences ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,0210 nano-technology ,Layer (electronics) ,ComputingMilieux_MISCELLANEOUS ,media_common - Abstract
In magnetic tunnel junctions (MTJ), synthetic antiferromagnets (SAF) are usually used as reference layer to minimize dipolar interactions induced between this layer and the free layer (FL). We show here that the use of SAF allows us to reduce the asymmetry of the FL reversal due to stray fields in nanosized MTJs with perpendicular magnetic anisotropy.
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- 2010
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36. Metallic Mg insertion in rf deposited MgO barrier
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R. C. Sousa, B. Dieny, M. M. C. Souza, S. Auffret, Clarisse Ducruet, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and ANR-07-NANO-052-02 project
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010302 applied physics ,[PHYS]Physics [physics] ,Materials science ,Magnetoresistance ,Magnesium ,Annealing (metallurgy) ,Significant difference ,Analytical chemistry ,General Physics and Astronomy ,Magnetic tunnelling ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,law.invention ,Metal ,Tunnel magnetoresistance ,Nuclear magnetic resonance ,chemistry ,law ,visual_art ,0103 physical sciences ,visual_art.visual_art_medium ,Crystallization ,0210 nano-technology - Abstract
International audience; Metallic Mg insertions in rf deposited MgO barrier of magnetic tunnel junctions structures were investigated in a resistance-area (RA) range from 1 to 1000 $\Omega$$\mu$m$^2$. For the first time, investigations on Mg insertions above the MgO barrier and simultaneously on both sides of the barrier are reported. It is shown that for RA larger than 5 $\Omega$$\mu$m$^2$, a bottom Mg insertion does not improve the tunnel magnetoresistance (TMR) ratio compared to a sample with no Mg insertion. Furthermore, a top Mg insertion yields a lower TMR ratio decreasing as the Mg thickness is increased. On the other side, for RA lower than 5 $\Omega$$\mu$m$^2$, there is no significant difference between top and bottom Mg insertions indicating that in this region, the MgO crystallization occurs mainly during the annealing process. In the RA range investigated, there is no significant difference in coupling field for different insertions. In very low RA regions between 1 and 10 $\Omega$$\mu$m$^2$, an increase in TMR is observed for 0.3 nm insertions simultaneously below an above the barrier.
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- 2010
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37. Influence of thermal annealing on the perpendicular magnetic anisotropy of Pt/Co/AlOx trilayers
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Bernard Dieny, Bernard Rodmacq, Aurelien Manchon, Clarisse Ducruet, and Stéphane Auffret
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Materials science ,Condensed matter physics ,Magnetoresistance ,Perpendicular magnetic anisotropy ,Annealing (metallurgy) ,chemistry.chemical_element ,Plasma ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,Magnetic anisotropy ,Nuclear magnetic resonance ,chemistry ,Hall effect ,Platinum ,Cobalt - Abstract
The influence of thermal annealing on Pt/Co/AlOx trilayers has been investigated up to $450\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ as a function of the plasma oxidation time of the AlOx layer. Both magnetic properties of the Co layer and transport properties are strongly modified upon annealing. The perpendicular magnetic anisotropy reaches very large values, while the Hall angle increases with annealing temperature. This study reveals that this trilayer system possesses tunable magnetic anisotropy properties, which can be controlled by varying either oxidation time or annealing temperature. These results are compared with those obtained on standard Pt/Co/Pt trilayers which show, on the contrary, a continuous degradation of their magnetic properties upon annealing.
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- 2009
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38. X-ray analysis of the magnetic influence of oxygen in Pt/Co/AlOx trilayers
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Aurelien Manchon, M. Hochstrasser, B. Dieny, G. Panaccione, Clarisse Ducruet, Stéphane Auffret, Stefania Pizzini, B. Rodmacq, Vojtech Uhlir, Jan Vogel, Lucien Lombard, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Micro et NanoMagnétisme (MNM), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratory for Solid State Physics (ETH Zurich), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratory TASC (TASC), INFM-CNR, Micro et NanoMagnétisme (NEEL - MNM), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,Nanostructure ,oxidation ,perpendicular magnetic anisotropy ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,01 natural sciences ,Oxygen ,PACS: 75.70.Cn, 75.30.Gw, 79.60.Jv, 81.65.Mq ,Condensed Matter::Materials Science ,X-ray photoelectron spectroscopy ,0103 physical sciences ,platinum ,010306 general physics ,Spectroscopy ,magnetic multilayers ,MAGNETOCRYSTALLINE ANISOTROPY ,[PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall] ,TUNNEL-JUNCTION ,X-ray photoelectron spectra ,Heterojunction ,PERPENDICULAR ANISOTROPY ,aluminium compounds ,021001 nanoscience & nanotechnology ,ORBITAL-MOMENT ,cobalt ,Magnetic anisotropy ,chemistry ,AU MULTILAYERS ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,0210 nano-technology ,Platinum ,Cobalt - Abstract
International audience; X-ray spectroscopy measurements have been performed on a series of Pt/Co/AlOx trilayers to investigate the role of Co oxidation in the perpendicular magnetic anisotropy at the Co/AlOx interface. It is observed that varying the degree of oxidation modifies the magnetic properties of the Co layer, inducing a magnetic anisotropy crossover from in plane to out of plane. The microscopic structural properties are analyzed via x-ray photoelectron spectroscopy measurements. It is shown that increasing the oxidation time enhances the amount of interfacial oxide, which may be at the origin of perpendicular magnetic anisotropy.
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- 2008
- Full Text
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39. X-Ray Analysis of Oxygen-induced Perpendicular Magnetic Anisotropy in Pt/Co/AlOx trilayer
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Aurélien Manchon, Stefania Pizzini, Jan Vogel, Vojtech Uhlir, Lucien Lombard, Clarisse Ducruet, Stéphane Auffret, Bernard Rodmacq, Bernard Dieny, Michael Hochstrasser, Giancarlo Panaccione, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Micro et NanoMagnétisme (NEEL - MNM), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Institute of Physical Engineering, Brno University of Technology [Brno] (BUT), Laboratory for Solid State Physics, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratory TASC, INFM-CNR, Micro et NanoMagnétisme (MNM), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
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Condensed Matter - Materials Science ,75.47.-m,75.70.Cn,72.25.Ba,73.20.-r,73.40.Rw ,Condensed Matter - Mesoscale and Nanoscale Physics ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,X-ray photoelectron spectroscopy (XPS) ,Condensed Matter::Materials Science ,X-ray magnetic Circular Dichroism (XMCD) ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,X-ray Absorption spectroscopy (XAS) ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Perpendicular Magnetic Anisotropy ,Magnetic Tunnel Junctions ,[PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall] - Abstract
International audience; X-ray spectroscopy measurements have been performed on a series of Pt/Co/AlOx trilayers to investigate the role of Co oxidation in the perpendicular magnetic anisotropy of the Co/AlOx interface. It is observed that high temperature annealing modifies the magnetic properties of the Co layer, inducing an enhancement of the perpendicular magnetic anisotropy. The microscopic structural properties are analyzed via X-ray Absorption Spectroscopy, X-ray Magnetic Circular Dichroism and X-ray Photoelectron Spectroscopy measurements. It is shown that annealing enhances the amount of interfacial oxide, which may be at the origin of a strong perpendicular magnetic anisotropy.
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- 2007
- Full Text
- View/download PDF
40. Analysis of anisotropy crossover due to oxygen in Pt/Co/MOx trilayer
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Aurélien Manchon, Clarisse Ducruet, Lucien Lombard, Stéphane Auffret, Bernard Rodmacq, Bernard Dieny, Stefania Pizzini, Jan Vogel, Vojtech Uhlir, Michael Hochstrasser, Giancarlo Panaccione, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Consortium de Recherches pour l'Emergence des Technologies Avancées (CRETA), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Micro et NanoMagnétisme (NEEL - MNM), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Laboratory for Solid State Physics, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratory TASC, INFM-CNR, Micro et NanoMagnétisme (MNM), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
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Condensed Matter - Materials Science ,X-ray photoelectron spectroscopy ,Magnetic tunnel junctions ,Condensed Matter::Materials Science ,75.47.-m,75.70.Cn,72.25.Ba,73.20.-r,73.40.Rw ,Condensed Matter - Mesoscale and Nanoscale Physics ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,X-ray absorption spectroscopy ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Perpendicular magnetic anisotropy ,[PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall] - Abstract
International audience; Extraordinary Hall effect and X-ray spectroscopy measurements have been performed on a series of Pt/Co/MOx trilayers (M=Al, Mg, Ta...) in order to investigate the role of oxidation in the onset of perpendicular magnetic anisotropy at the Co/MOx interface. It is observed that varying the oxidation time modifies the magnetic properties of the Co layer, inducing a magnetic anisotropy crossover from in-plane to out-of-plane. We focused on the influence of plasma oxidation on Pt/Co/AlOx perpendicular magnetic anisotropy. The interfacial electronic structure is analyzed via X-ray photoelectron spectroscopy measurements. It is shown that the maximum of out-of-plane magnetic anisotropy corresponds to the appearance of a significant density of Co-O bondings at the Co/AlOx interface.
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- 2007
- Full Text
- View/download PDF
41. Investigation of polycrystalline Nd2Fe14B texturing by solidification in a magnetic field
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P. de Rango, C Paduani, Sophie Rivoirard, Robert Tournier, Clarisse Ducruet, Univ Fed Santa Catarina, Dept Fis, Univ Fed Santa Catarina, Consortium de Recherches pour l'Emergence des Technologies Avancées (CRETA), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Cristallographie, and Centre National de la Recherche Scientifique (CNRS)
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010302 applied physics ,Condensed matter physics ,Magnetism ,rare-earth ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Magnetocrystalline anisotropy ,01 natural sciences ,transition metal ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Magnetization ,Magnetic anisotropy ,magnetocrystalline anisotropy ,magnetism ,0103 physical sciences ,Melting point ,[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] ,Crystallite ,0210 nano-technology ,Anisotropy - Abstract
International audience; A polycrystalline sample of Nd2Fe14B was prepared by induction melting and solidification in an intense applied magnetic field, to study the alignment due to residual magnetocrystalline anisotropy of this compound near the melting point. A well-defined direction of the thermal gradient perpendicular to the magnetic field was achieved by means of an appropriate experimental set-up. The results of measurements indicate that the sample is substantially textured, but not in parallel to the elaboration field. A numerical method is utilized for the determination of anisotropy parameters in Nd2Fe14B compound, involving the analysis of measured magnetization curves. The minimization of the free-energy density, expanded in terms of these constants, is performed to determine the sub-lattice terms which are necessary to calculate the polarization curves. A fitting of the measured magnetization curves obtained at room temperature is realized to obtain the anisotropy constants, texture parameters and saturation magnetization.
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- 2001
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42. Electrical and thermal spin accumulation in germanium
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A. Jain, A. Barski, Matthieu Jamet, Vincent Baltz, Emmanuel Augendre, J. C. Le Breton, L. Louahadj, Pascale Bayle-Guillemaud, Henri Jaffrès, Céline Vergnaud, Clarisse Ducruet, J.-M. George, Eric Prestat, Jean-Philippe Attané, C. Portemont, Laurent Vila, Alain Marty, J. Peiro, Nanostructures et Magnétisme (NM), Service de Physique des Matériaux et Microstructures (SP2M - UMR 9002), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des Matériaux par Microscopie Avancée (LEMMA ), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), CROCUS Technology, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), THALES [France]-Centre National de la Recherche Scientifique (CNRS), and Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG)
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,FOS: Physical sciences ,chemistry.chemical_element ,Germanium ,02 engineering and technology ,01 natural sciences ,Signal ,Spin wave ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,0103 physical sciences ,Thermoelectric effect ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,010306 general physics ,Spin-½ ,Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed matter physics ,Materials Science (cond-mat.mtrl-sci) ,021001 nanoscience & nanotechnology ,Temperature gradient ,chemistry ,Ferromagnetism ,Spin diffusion ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology - Abstract
In this letter, we first show electrical spin injection in the germanium conduction band at room temperature and modulate the spin signal by applying a gate voltage to the channel. The corresponding signal modulation agrees well with the predictions of spin diffusion models. Then by setting a temperature gradient between germanium and the ferromagnet, we create a thermal spin accumulation in germanium without any tunnel charge current. We show that temperature gradients yield larger spin accumulations than pure electrical spin injection but, due to competing microscopic effects, the thermal spin accumulation in germanium remains surprisingly almost unchanged under the application of a gate voltage to the channel., 7 pages, 3 figures
- Published
- 2012
- Full Text
- View/download PDF
43. IrMn and FeMn blocking temperature dependence on heating pulse width
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I. L. Prejbeanu, Erwan Gapihan, Y. Dahmane, R. C. Sousa, Bernard Dieny, Lucien Lombard, Cristian Papusoi, Y. Conraux, Jean Pierre Nozieres, C. Portemont, Clarisse Ducruet, and A. Schuhl
- Subjects
Magnetization ,Long pulse ,Materials science ,Condensed matter physics ,Blocking (radio) ,General Physics and Astronomy ,Antiferromagnetism ,Pulse-width modulation ,Quasistatic process ,Power density ,Power (physics) - Abstract
We have determined the write power density dependence on heating pulse width and antiferromagnet (AF) thickness using magnetic tunnel junctions whose storage layer is exchange biased with IrMn or FeMn. An increase in write power density needed to write the storage layer has been observed for both AF as pulse width is decreased from 0.1 ms to 10 ns. Quasistatic blocking temperatures (Tb) were measured on both full sheet and patterned samples, showing a reduction in Tb for patterned samples which we link to process induced damages. Power-temperature relationship was established based on a correspondence between writing power for long pulse duration and quasistatic Tb measurement. Both write power density and associated temperature results show a dependence of the Tb on AF thickness at pulse width as short as 10 ns. Particularly for IrMn, the relationship between write power and pulse width becomes weakly dependent on the AF thickness above a certain AF thickness. The write power density is significantly low...
- Published
- 2010
- Full Text
- View/download PDF
44. Off-axis deposition of Al layer for low resistance tunnel barrier
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R. C. Sousa, S. Auffret, Bernard Dieny, C. Portemont, Clarisse Ducruet, Ioan Lucian Prejbeanu, and S. Bandiera
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Materials science ,Magnetoresistance ,Metallurgy ,General Physics and Astronomy ,Sputter deposition ,Condensed Matter::Materials Science ,Tunnel effect ,Tunnel magnetoresistance ,Surface coating ,Sputtering ,Condensed Matter::Superconductivity ,Wafer ,Thin film ,Composite material - Abstract
In order to improve the magnetic and electrical properties of low resistance alumina based magnetic tunnel junctions, an off-axis method of sputtering has been investigated. It is shown that the tunnel magnetoresistance ratio can be greatly increased when there is an offset between the target and the wafer axes during the deposition of the ultrathin aluminum layer (off-axis sputtering) prior to its natural oxidation. The ferromagnetic coupling between the pinned and the free layer through the alumina barrier is also reduced compared to a classical on-axis deposition. This observation is interpreted as an improvement of the barrier quality, reducing both the roughness and the pinholes density. We assume that when the Al layer is sputtered off-axis, the magnetic and aluminum layers are protected from energetic neutralized Ar atoms bombardment.
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- 2010
- Full Text
- View/download PDF
45. Spin-transfer effect and its use in spintronic components
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R. C. Sousa, J. Herault, M.-C. Cyrille, Guillaume Prenat, J.-P. Nozieres, Ioan Lucian Prejbeanu, B. Dieny, B. Delaet, Liliana D. Buda-Prejbeanu, Clarisse Ducruet, Cristian Papusoi, U. Ebels, D. Houssameddine, S. Auffret, B. Rodmacq, and Olivier Redon
- Subjects
Physics ,Magnetoresistive random-access memory ,Spintronics ,Magnetism ,business.industry ,Electrical engineering ,Spin valve ,Bioengineering ,Giant magnetoresistance ,Condensed Matter Physics ,Non-volatile memory ,Tunnel magnetoresistance ,Nuclear magnetic resonance ,CMOS ,Materials Chemistry ,Electrical and Electronic Engineering ,business - Abstract
Spin-electronics is a very rapidly expanding area of R&D which merges magnetism and electronics (Nobel Prize 2007). Since the discovery of giant magnetoresistance in 1988, several breakthroughs have further boosted this field (spin-valves 1990, tunnel magnetoresistance 1995, spin transfer 1996, voltage controlled magnetic properties 2004). The phenomenon of spin-transfer is particularly attractive both from fundamental and applied view points. It provides a new way to manipulate the magnetisation of magnetic nanostructures by a spin-polarised current. Spinelectronics has found applications in hard disk drives (1998) and more recently in non-volatile standalone memories (MRAM = Magnetic Random Access Memory). The spin-transfer phenomenon provides a new write scheme in MRAM yielding a much better scalability of these devices towards the 22 nm node. Furthermore, besides MRAMs, hybrid CMOS/magnetic technology can yield a totally new approach in the way electronic devices are designed. Most CMOS devices such as microprocessors are based on Von Neumann architecture in which logic and memories are separate components. The unique set of characteristics combined within magnetic tunnel junctions: cyclability, switching speed, scalability, makes it possible to conceive novel electronic systems in which logic and memory are intimately combined in non-volatile logic components (concept of non-volatile CPU). The spin-transfer phenomenon can also be used to generate large amplitude steady magnetic excitations in magnetic nanostructures. This phenomenon can also be used to conceive new frequency tunable radiofrequency oscillators. The latter are very attractive for wireless applications which require scanning large frequency bandwidth.
- Published
- 2010
- Full Text
- View/download PDF
46. Nanosecond magnetic switching of ferromagnet-antiferromagnet bilayers in thermally assisted magnetic random access memory
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B. Delaet, O. Redon, J. Herault, B. Dieny, Y. Conraux, Marie-Claire Cyrille, Clarisse Ducruet, C. Portemont, R. C. Sousa, I. L. Prejbeanu, and K. Mackay
- Subjects
Nuclear magnetic resonance ,Materials science ,Condensed matter physics ,Ferromagnetism ,Field (physics) ,General Physics and Astronomy ,Antiferromagnetism ,Pulse duration ,Biasing ,Time domain ,Nanosecond ,Current density - Abstract
The magnetic switching of the exchange biased storage layer in thermally assisted magnetic random access memory cells has been studied in the nanosecond time domain. Under reversed static external field, the magnetic tunnel junctions (MTJs) were subjected to current heating pulses long enough to heat the structure above the blocking temperature of the antiferromagnetic layer. The magnetic response of the storage layer was characterized by single-shot real-time measurement of MTJ resistance. The switching of the storage layer exhibits stochastic fluctuations. Nevertheless, using a heating current density of 4.7×106 A/cm2 corresponding to a bias voltage of 1.8 V, the switching takes place in less than 4 ns under 5 mT. Interestingly, the probability of switching versus pulse duration exhibits characteristic periodic steps which are ascribed to a combined effect of the applied field and spin transfer produced by the heating current pulses.
- Published
- 2009
- Full Text
- View/download PDF
47. Analysis of oxygen induced anisotropy crossover in Pt/Co/MOx trilayers
- Author
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G. Panaccione, V. Uhlíř, Clarisse Ducruet, Stefania Pizzini, Jan Vogel, Stéphane Auffret, B. Rodmacq, Aurelien Manchon, M. Hochstrasser, Lucien Lombard, and B. Dieny
- Subjects
010302 applied physics ,X-ray absorption spectroscopy ,Materials science ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,PERPENDICULAR ANISOTROPY ,02 engineering and technology ,Electronic structure ,Plasma ,021001 nanoscience & nanotechnology ,01 natural sciences ,INTERFACE ,Condensed Matter::Materials Science ,Magnetic anisotropy ,chemistry ,X-ray photoelectron spectroscopy ,AU MULTILAYERS ,Hall effect ,0103 physical sciences ,0210 nano-technology ,Spectroscopy ,Cobalt ,MAGNETOCRYSTALLINE ANISOTROPY ,MAGNETIC TUNNEL-JUNCTIONS - Abstract
Extraordinary Hall effect and x-ray spectroscopy measurements have been performed on a series of Pt/Co/MOx trilayers (M=Al, Mg, Ta, etc.) in order to investigate the role of oxidation in the onset of perpendicular magnetic anisotropy at the Co/MOx interface. It is observed that varying the plasma oxidation time modifies the magnetic properties of the Co layer, inducing a magnetic anisotropy crossover from in plane to out of plane. We focused on the influence of plasma oxidation on Pt/Co/AlOx perpendicular magnetic anisotropy. The interfacial electronic structure is analyzed via x-ray photoelectron spectroscopy measurements. It is shown that the maximum of out-of-plane magnetic anisotropy corresponds to the appearance of a significant density of Co-O bondings at the Co/AlOx interface. (C) 2008 American Institute of Physics.
- Published
- 2008
- Full Text
- View/download PDF
48. Magnetoresistance in Co∕Pt based magnetic tunnel junctions with out-of-plane magnetization
- Author
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B. Rodmacq, B. Carvello, Clarisse Ducruet, S. Auffret, Gilles Gaudin, and B. Dieny
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Materials science ,Condensed matter physics ,Magnetic moment ,Magnetoresistance ,Magnetometer ,General Physics and Astronomy ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,law.invention ,Condensed Matter::Materials Science ,Magnetization ,Magnetic anisotropy ,Ferromagnetism ,law ,Hall effect ,Antiferromagnetism - Abstract
Submicron magnetic tunnel junctions exhibiting perpendicular magnetic anisotropy have been prepared by sputtering. They associate a hard and a soft electrode based on Co∕Pt multilayers, separated by an amorphous alumina barrier. The soft electrode is either free or exchange biased by an antiferromagnetic layer. The magnetoresistance ratio reaches 8% at room temperature after patterning junctions with diameter down to 200nm. The macroscopic magnetic properties were investigated by extraordinary Hall effect and conventional magnetometry measurements. The magnetic moments of both electrodes are out of plane. Two well-separated switching fields allow the realization of well-defined parallel and antiparallel configurations of the magnetizations.
- Published
- 2008
- Full Text
- View/download PDF
49. Sizable room-temperature magnetoresistance in cobalt based magnetic tunnel junctions with out-of-plane anisotropy
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Bernard Rodmacq, Baptiste Carvello, Bernard Dieny, Eric Gautier, Clarisse Ducruet, Gilles Gaudin, and Stéphane Auffret
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SQUID ,Magnetic anisotropy ,Materials science ,Physics and Astronomy (miscellaneous) ,Magnetic moment ,Condensed matter physics ,Magnetoresistance ,Hall effect ,Magnetometer ,law ,Coercivity ,law.invention ,Nanopillar - Abstract
Submicron alumina based magnetic tunnel junctions (MTJs) using electrodes with out-of-plane magnetic anisotropy were prepared and characterized. Both electrodes are industry-compatible Co∕Pt multilayers. The magnetic properties of the unpatterned samples have been investigated through superconducting quantum interference device (SQUID) magnetometry and extraordinary Hall effect: both electrodes have fully out-of-plane magnetic moments and nonoverlapping coercive fields. Transport measurements on the submicron MTJs showed a magnetoresistance (MR) ratio reaching 8% at room temperature. Nanopillars with diameters of 800, 400, and 200nm patterned from the same wafer show the expected out-of-plane magnetic properties and similar resistance×area products (RA) and MR ratios. The I(V) characteristics of pillars with diameters of 800 and 400nm could be accounted for with reasonable barrier heights and widths.
- Published
- 2008
- Full Text
- View/download PDF
50. Laser generated plasmas characterized under magnetic field
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Dominique Givord, Clarisse Ducruet, N. Kornilov, and C. de Julián Fernández
- Subjects
Laser ablation ,Physics and Astronomy (miscellaneous) ,Physics::Plasma Physics ,Chemistry ,Atom ,Melting point ,Plasma diagnostics ,Plasma ,Atomic physics ,Charged particle ,Magnetic field ,Ion - Abstract
The confinement of laser generated plasmas by a magnetic field is exploited to analyze the properties of plasmas of different materials. The ablation threshold is approximately proportional to Cv(Tmelt−300) (Tmelt=melting temperature, Cv=specific heat). The ablation rate is related to the boiling enthalpy. From aluminum to molybdenum, the increase in the proportion of ions within the plume is discussed by considering the energy per atom available for plasma heating. While negligible in zero magnetic field, ion recombination effects are significant under field. This is attributed to the higher plasma density and to the decrease in the mean energy of the detected ions.
- Published
- 2006
- Full Text
- View/download PDF
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