6 results on '"Vogel, Jan"'
Search Results
2. Magnetic and magneto-transport properties of Mn4N thin films by Ni substitution and their possibility of magnetic compensation.
- Author
-
Komori, Taro, Gushi, Toshiki, Anzai, Akihito, Vila, Laurent, Attané, Jean-Philippe, Pizzini, Stefania, Vogel, Jan, Isogami, Shinji, Toko, Kaoru, and Suemasu, Takashi
- Subjects
MAGNETIZATION ,THIN films ,SPINTRONICS ,MANGANESE nitrides ,FERRIMAGNETISM - Abstract
Ferrimagnets are of interest in spintronics owing to the enhancement of spin transfer and spin–orbit torque in the vicinity of the magnetic compensation point. Here, we study the possibility of achieving compensation at room temperature in Mn
4−x Nix N films grown on SrTiO3 (001) substrates by molecular beam epitaxy. The magnetic and magneto-transport properties of 30-nm-thick epitaxial Mn4−x Nix N films (x = 0, 0.1, 0.25, and 0.5) were investigated. Ni introduction in Mn4 N causes the spontaneous magnetization (MS ) to decrease by 45% at x = 0.1 and by 75% at x = 0.25. All samples exhibited the perpendicular magnetic anisotropy required for spintronic applications as well as displaying a sharp magnetization reversal. Remarkably, the sign of the anomalous Hall resistivity changed in the samples between x = 0.1 and 0.25. Further, the magnetization increased for x = 0 and 0.1 and decreased for x = 0.25 when the temperature was decreased. Based on these results, we propose that there is a magnetic compensation composition between x = 0.1 and 0.25, where the magnetization of Mn4−x Nix N becomes zero at room temperature. The small MS and perpendicular magnetic anisotropy of the Mn4−x Nix N thin films, thus, make them suitable candidates for use in spin transfer torque-based devices. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
3. Magnetic domain pinning in an anisotropy-engineered GdTbFe thin film.
- Author
-
Konings, Stan, Miguel, Jorge, Goedkoop, Jeroen, Camarero, Julio, and Vogel, Jan
- Subjects
THIN films ,ANISOTROPY ,ION bombardment ,X-rays ,MAGNETIC resonance microscopy ,MAGNETISM - Abstract
Focused ion beam irradiation was used to reduce locally the perpendicular anisotropy of magnetic thin films in rectangular lattices of 50 nm sized dots. The effect of the anisotropy patterns, differing in ion fluence and interdot spacing, on the magnetization reversal process was determined in q space with x-ray resonant magnetic scattering and in real space with magnetic force microscopy. At remanence only a slight alignment of the irregularly shaped domains is observed. In perpendicular magnetic fields, however, the high field bubble domains display a pronounced localization on the dots, showing that this form of local anisotropy reduction is a highly efficient way of domain positioning. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
4. Nucleation of magnetisation reversal, from nanoparticles to bulk materials
- Author
-
Vogel, Jan, Moritz, Jérôme, and Fruchart, Olivier
- Subjects
- *
NUCLEATION , *MAGNETIZATION , *THIN films , *SURFACE tension , *ANISOTROPY , *PROPERTIES of matter - Abstract
Abstract: We review models for the nucleation of magnetisation reversal, i.e. the formation of a region of reversed magnetisation in an initially magnetically saturated system. For small particles, models for collective reversal, either uniform (Stoner–Wohlfarth model) or non-uniform like curling, provide good agreement between theory and experiment. For microscopic objects and thin films, we consider two models, uniform (Stoner–Wohlfarth) reversal inside a nucleation volume and a droplet model, where the free energy of an inverse bubble is calculated, taking into account volume energy (Zeeman energy) and surface tension (domain wall energy). In macroscopic systems, inhomogeneities in magnetic properties cause a distribution of energy barriers for nucleation, which strongly influences effects of temperature and applied field on magnetisation reversal. For these systems, macroscopic material parameters like exchange interaction, spontaneous magnetisation and magnetic anisotropy can give an indication of the magnetic coercivity, but exact values for nucleation fields are, in general, hard to predict. To cite this article: J. Vogel et al., C. R. Physique 7 (2006). [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
5. The Skyrmion Switch: Turning Magnetic Skyrmion Bubbles on and off with an Electric Field.
- Author
-
Schott, Marine, Bernand-Mantel, Anne, Ranno, Laurent, Pizzini, Stefania, Vogel, Jan, Béa, Hélène, Baraduc, Claire, Auffret, Stéphane, Gaudin, Gilles, and Givord, Dominique
- Subjects
- *
SKYRMIONS , *MAGNETIC bubbles , *ELECTRIC fields , *NANOSTRUCTURED materials , *NUCLEATION , *SPINTRONICS - Abstract
Nanoscale magnetic skyrmions are considered as potential information carriers for future spintronics memory and logic devices. Such applications will require the control of their local creation and annihilation, which involves so far solutions that are either energy consuming or difficult to integrate. Here we demonstrate the control of skyrmion bubbles nucleation and annihilation using electric field gating, an easily integrable and potentially energetically efficient solution. We present a detailed stability diagram of the skyrmion bubbles in a Pt/Co/oxide trilayer and show that their stability can be controlled via an applied electric field. An analytical bubble model with the Dzyaloshinskii-Moriya interaction imbedded in the domain wall energy accounts for the observed electrical skyrmion switching effect. This allows us to unveil the origin of the electrical control of skyrmions stability and to show that both magnetic dipolar interaction and the Dzyaloshinskii-Moriya interaction play an important role in the skyrmion bubble stabilization. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. Magnetization dynamics : from single films to coupled systems
- Author
-
Pennec, Yan, Vogel, Jan, Laboratoire Louis Néel (LLN), Centre National de la Recherche Scientifique (CNRS), Université Joseph-Fourier - Grenoble I, and Fontaine Alain(jan.vogel@grenoble.cnrs.fr)
- Subjects
ferromagnetic/antiferromagnetic coupling ,couches minces ,domaines magnétiques ,magnetization dynamics ,orange-peel coupling ,magnetic domains ,magneto-optics ,couplage peau d'orange ,couplage ferromagnétique-antiferromagnétique ,thin films ,magnétisme ,magnetism ,magnéto-optique ,dynamique de l'aimantation ,magnetic microscopy ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,microscopie magnétique ,[PHYS.COND] Physics [physics]/Condensed Matter [cond-mat] - Abstract
The first part of this thesis describes the magneto-optical effects (from visible light to X-rays), the ways to produce dynamical magnetic fields and the different magnetometres that have been developed. These instruments allow studying dynamics over a time scale from 50 ps to several hours, with a spatial resolution down to 100 nm. The second part is dedicated to a short presentation of magnetism and theoretical approaches to magnetization dynamics. The third part presents studies on a garnet film, where the dynamics is dominated by precessional effects, and a Co/Pt multilayer where thermally activated effects (nucleation, propagation) dominate. In the fourth and final part, I start with the presentation of a study on coupled ferro/antiferromagnetic Co/NiO bilayers. Then results of a study on the disappearance of the magnetostatic orange-peel coupling at high reversal speed in ferromagnetic/non-magnetic/ferromagnetic trilayers deposited on step-bunched substrates are presented., La première partie de cette thèse décrit les effets magnéto-optiques (du visible aux Rayons X), les techniques de production dynamique de champ magnétique ainsi que les différents magnétomètres élaborés. Ces instruments permettent une étude sur une plage dynamique très importante de 50 ps à plusieurs heures avec une résolution spatiale jusqu'à 100 nm. Suit une partie consacrée à une présentation succincte du magnétisme et des approches théoriques de la dynamique de l'aimantation. La troisième partie est consacrée à l'étude d'un film de grenat où la dynamique est dominée par des effets de précession de l'aimantation, puis d'une multicouche Co/Pt où la dynamique est dominée par des effets d'activation thermique. Enfin la quatrième partie présente l'étude des systèmes couplés Ferro-AntiFerro Co/NiO puis une étude sur la disparition du couplage peau d'orange à haute vitesse de renversement de l'aimantation sur des tricouches Ferro-Nonmagnétique-Ferro déposées sur des substrats à accumulation de marches.
- Published
- 2003
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.