12 results on '"Deranlot, Cyrile"'
Search Results
2. Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmion at room temperature
- Author
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Moreau-Luchaire, Constance, Moutafis, Christoforos, Reyren, Nicolas, Sampaio, José J., Bouzehouane, Karim, Deranlot, Cyrile, Warnicke, P., Vaz, C. A. F., Van Horne, N., Garcia, Karin, Wohlhüter, P., George, Jean-Marie, Weigand, M., Raabe, Jörg, Cros, Vincent, and Fert, Albert
- Subjects
Condensed Matter - Materials Science - Abstract
Facing the ever-growing demand for data storage will most probably require a new paradigm. Nanoscale magnetic skyrmions are anticipated to solve this issue as they are arguably the smallest spin textures in magnetic thin films in nature. We designed cobalt-based multilayered thin films where the cobalt layer is sandwiched between two heavy metals providing additive interfacial Dzyaloshinskii-Moriya interactions, which reach a value close to 2 mJ m-2 in the case of the Ir|Co|Pt asymmetric multilayers. Using a magnetization-sensitive scanning x-ray transmission microscopy technique, we imaged small magnetic domains at very low field in these multilayers. The study of their behavior in perpendicular magnetic field allows us to conclude that they are actually magnetic skyrmions stabilized by the large Dzyaloshinskii-Moriya interaction. This discovery of stable sub-100 nm individual skyrmions at room temperature in a technologically relevant material opens the way for device applications in a near future.
- Published
- 2016
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3. Electrical measurement of magnetic-field-impeded polarity switching of a ferromagnetic vortex core
- Author
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Sushruth, Manu, Fried, Jasper P., Anane, Abdelmadjid, Xavier, Stephane, Deranlot, Cyrile, Kostylev, Mikhail, Cros, Vincent, and Metaxas, Peter J.
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Vortex core polarity switching in NiFe disks has been evidenced using an all-electrical rectification scheme. Both simulation and experiments yield a consistent loss of the rectified signal when driving the core at high powers near its gyrotropic resonant frequency. The frequency range over which the loss occurs grows and shifts with increasing signal power, consistent with non-linear core dynamics and periodic switching of the core polarity induced by the core attaining its critical velocity. We demonstrate that core polarity switching can be impeded by displacing the core towards the disk's edge where an increased core stiffness reduces the maximum attainable core velocity., Comment: 6 pages, 5 figures
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- 2016
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4. Graphene-Passivated Nickel as an Oxidation-Resistant Electrode for Spintronics
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Dlubak, Bruno, Martin, Marie-Blandine, Weatherup, Robert S., Yang, Heejun, Deranlot, Cyrile, Blume, Raoul, Schloegl, Robert, Fert, Albert, Anane, Abdelmadjid, Hofmann, Stephan, Seneor, Pierre, and Robertson, John
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We report on graphene-passivated ferromagnetic electrodes (GPFE) for spin devices. GPFE are shown to act as spin-polarized oxidation-resistant electrodes. The direct coating of nickel with few layer graphene through a readily scalable chemical vapour deposition (CVD) process allows the preservation of an unoxidized nickel surface upon air exposure. Fabrication and measurement of complete reference tunneling spin valve structures demonstrates that the GPFE is maintained as a spin polarizer and also that the presence of the graphene coating leads to a specific sign reversal of the magneto-resistance. Hence, this work highlights a novel oxidation-resistant spin source which further unlocks low cost wet chemistry processes for spintronics devices.
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- 2014
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5. Highly efficient spin transport in epitaxial graphene on SiC
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Dlubak, Bruno, Martin, Marie-Blandine, Deranlot, Cyrile, Servet, Bernard, Xavier, Stéphane, Mattana, Richard, Sprinkle, Mike, Berger, Claire, De Heer, Walt A., Petroff, Frédéric, Anane, Abdelmadjid, Seneor, Pierre, and Fert, Albert
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Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Spin information processing is a possible new paradigm for post-CMOS (complementary metal-oxide semiconductor) electronics and efficient spin propagation over long distances is fundamental to this vision. However, despite several decades of intense research, a suitable platform is still wanting. We report here on highly efficient spin transport in two-terminal polarizer/analyser devices based on high-mobility epitaxial graphene grown on silicon carbide. Taking advantage of high-impedance injecting/detecting tunnel junctions, we show spin transport efficiencies up to 75%, spin signals in the mega-ohm range and spin diffusion lengths exceeding 100 {\mu}m. This enables spintronics in complex structures: devices and network architectures relying on spin information processing, well beyond present spintronics applications, can now be foreseen.
- Published
- 2013
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6. A ferroelectric memristor
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Chanthbouala, André, Garcia, Vincent, Cherifi, Ryan O., Bouzehouane, Karim, Fusil, Stéphane, Moya, Xavier, Xavier, Stéphane, Yamada, Hiroyuki, Deranlot, Cyrile, Mathur, Neil D., Bibes, Manuel, Barthélémy, Agnès, and Grollier, Julie
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Condensed Matter - Materials Science - Abstract
Memristors are continuously tunable resistors that emulate synapses. Conceptualized in the 1970s, they traditionally operate by voltage-induced displacements of matter, but the mechanism remains controversial. Purely electronic memristors have recently emerged based on well-established physical phenomena with albeit modest resistance changes. Here we demonstrate that voltage-controlled domain configurations in ferroelectric tunnel barriers yield memristive behaviour with resistance variations exceeding two orders of magnitude and a 10 ns operation speed. Using models of ferroelectric-domain nucleation and growth we explain the quasi-continuous resistance variations and derive a simple analytical expression for the memristive effect. Our results suggest new opportunities for ferroelectrics as the hardware basis of future neuromorphic computational architectures.
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- 2012
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7. Unravelling the role of the interface for spin injection into organic semiconductors
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Barraud, Clément, Seneor, Pierre, Mattana, Richard, Fusil, Stéphane, Bouzehouane, Karim, Deranlot, Cyrile, Graziosi, Patrizio, Hueso, Luis, Bergenti, Ilaria, Dediu, Valentin, Petroff, Frédéric, and Fert, Albert
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Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Whereas spintronics brings the spin degree of freedom to electronic devices, molecular/organic electronics adds the opportunity to play with the chemical versatility. Here we show how, as a contender to commonly used inorganic materials, organic/molecular based spintronics devices can exhibit very large magnetoresistance and lead to tailored spin polarizations. We report on giant tunnel magnetoresistance of up to 300% in a (La,Sr)MnO3/Alq3/Co nanometer size magnetic tunnel junction. Moreover, we propose a spin dependent transport model giving a new understanding of spin injection into organic materials/molecules. Our findings bring a new insight on how one could tune spin injection by molecular engineering and paves the way to chemical tailoring of the properties of spintronics devices., Comment: Original version. Revised version to appear in Nature Physics.
- Published
- 2010
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8. High domain wall velocity at zero magnetic field induced by low current densities in spin-valve nanostripes
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Pizzini, Stefania, Uhlir, Vojtech, Vogel, Jan, Rougemaille, Nicolas, Laribi, Sana, Cros, Vincent, Jimenez, Erika, Camarero, Julio, Tieg, Carsten, Bonet, Edgar, Bonfim, Marlio, Mattana, Richard, Deranlot, Cyrile, Petroff, Frédric, Ulysse, Christian, Faini, Giancarlo, and Fert, Albert
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Condensed Matter - Materials Science - Abstract
Current-induced magnetic domain wall motion at zero magnetic field is observed in the permalloy layer of a spin-valve-based nanostripe using photoemission electron microscopy. The domain wall movement is hampered by pinning sites, but in between them high domain wall velocities (exceeding 150 m/s) are obtained for current densities well below $10^{12} \unit{A/m^2}$, suggesting that these trilayer systems are promising for applications in domain wall devices in case of well controlled pinning positions. Vertical spin currents in these structures provide a potential explanation for the increase in domain wall velocity at low current densities., Comment: Published version, Applied Physics Express 2, 023003 (2009) http://dx.doi.org/10.1143/APEX.2.023003
- Published
- 2008
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9. Integration of multiferroic BiFe[O.sub.3] thin films into heterostructures for spintronics
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Bea, Helene, Bibes, Manuel, Herranz, Gervasi, Zhu, Xiao-Hong, Fusil, Stephane, Bouzehouane, Karim, Jacquet, Eric, Deranlot, Cyrile, and Barthelemy, Agnes
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Dielectric films -- Atomic properties ,Thin films -- Atomic properties ,Tunneling (Physics) -- Evaluation ,Ion exchange -- Observations ,Particle spin -- Observations ,Business ,Electronics ,Electronics and electrical industries - Abstract
The revival of multiferroics is motivated by their exciting physics and their ability to bring novel functionalities to a number of technological fields such as spintronics. The lack of room temperature ferroelectric ferromagnets is a problem and has driven most of the attention thus far to BiFe[O.sub.3], a ferroelectric weak-ferromagnet with both transition temperatures superior to 300K. In this paper, we report on the properties of BiFe[O.sub.3] heterostructures and focus on two types of approaches towards BiFe[O.sub.3]-based spintronics devices. One uses BiFe[O.sub.3] as an exchange bias layer in spin-valve structures in which the magnetic configuration is potentially switchable by an electric field, via the magnetoelectric coupling existing in BiFe[O.sub.3]. The other consists in integrating BiFe[O.sub.3] ultrathin films as tunnel barriers in magnetic tunnel junctions with the objective of exploiting their ferroelectric character along with their specific symmetry filtering properties. General perspectives for multiferroics in spintronics are given. Index Terms--Exchange bias, multiferroics, spintronics, tunneling.
- Published
- 2008
10. Interdependency of subsurface carbon distribution and graphene-catalyst interaction
- Author
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Weatherup, Robert S., Amara, Hakim, Blume, Raoul, Dlubak, Bruno, Bayer, Bernhard C., Diarra, Mamadou, Bahri, Mounib, Cabrero-Vilatela, Andrea, Caneva, Sabina, Kidambi, Piran R., Martin, Marie-Blandine, Deranlot, Cyrile, Seneor, Pierre, Schloegl, Robert, Ducastelle, François, Bichara, Christophe, Hofmann, Stephan, Weatherup, Robert [0000-0002-3993-9045], Hofmann, Stephan [0000-0001-6375-1459], and Apollo - University of Cambridge Repository
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0306 Physical Chemistry (incl. Structural) - Abstract
The dynamics of the graphene-catalyst interaction during chemical vapor deposition are investigated using in situ, time- and depth-resolved X-ray photoelectron spectroscopy, and complementary grand canonical Monte Carlo simulations coupled to a tight-binding model. We thereby reveal the interdependency of the distribution of carbon close to the catalyst surface and the strength of the graphene-catalyst interaction. The strong interaction of epitaxial graphene with Ni(111) causes a depletion of dissolved carbon close to the catalyst surface, which prevents additional layer formation leading to a self-limiting graphene growth behavior for low exposure pressures (10(-6)-10(-3) mbar). A further hydrocarbon pressure increase (to ∼10(-1) mbar) leads to weakening of the graphene-Ni(111) interaction accompanied by additional graphene layer formation, mediated by an increased concentration of near-surface dissolved carbon. We show that growth of more weakly adhered, rotated graphene on Ni(111) is linked to an initially higher level of near-surface carbon compared to the case of epitaxial graphene growth. The key implications of these results for graphene growth control and their relevance to carbon nanotube growth are highlighted in the context of existing literature.
- Published
- 2014
11. Recovering ferromagnetic metal surfaces to fully exploit chemistry in molecular spintronics
- Author
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Galbiati, Marta, primary, Delprat, Sophie, additional, Mattera, Michele, additional, Mañas-Valero, Samuel, additional, Forment-Aliaga, Alicia, additional, Tatay, Sergio, additional, Deranlot, Cyrile, additional, Seneor, Pierre, additional, Mattana, Richard, additional, and Petroff, Frédéric, additional
- Published
- 2015
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12. Integration of Multiferroic BiFeO3 Thin Films into Heterostructures for Spintronics.
- Author
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Héléne Béa, Bibes, Manuel, Herranz, Gervasi, Xiao-Hong Zhu, Fusil, Stéphane, Bouzehouane, Karim, Jacquet, Eric, Deranlot, Cyrile, and Barthélémy, Agnes
- Subjects
THIN films ,FERROELECTRIC crystals ,SPINTRONICS ,NANOTECHNOLOGY ,HETEROSTRUCTURES - Abstract
The revival of multiferroics is motivated by their exciting physics and their ability to bring novel functionalities to a number of technological fields such as spintronics. The lack of room temperature ferroelectric ferromagnets is a problem and has driven most of the attention thus far to BIFeO
3 , a ferroelectric weak-ferromagnet with both transition temperatures superior to 300K. In this paper, we report on the properties of BiFeO3 heterostructures and focus on two types of approaches towards BiFeO3 -based spintronics devices. One uses BiFeO3 as an exchange bias layer in spin-valve structures in which the magnetic configuration is potentially switchable by an electric field, via the magnetoelectric coupling existing in BiFeO3 . The other consists in integrating BiFeO3 ultrathin films as tunnel barriers in magnetic tunnel junctions with the objective of exploiting their ferroelectric character along with their specific symmetry filtering properties. General perspectives for multiferroics in spintronics are given. [ABSTRACT FROM AUTHOR]- Published
- 2008
- Full Text
- View/download PDF
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