A5035277786- Magnetic properties of thin films
- Advanced Electron Microscopy Techniques and Applications
- Carbon Nanotubes in Composites
- Magnetic Properties and Applications
- Electron and X-Ray Spectroscopy Techniques
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Characterization and Applications of Magnetic Nanoparticles
- Graphene research and applications
- Force Microscopy Techniques and Applications
- Theoretical and Computational Physics
- Diamond and Carbon-based Materials Research
- Surface and Thin Film Phenomena
- Advanced X-ray Imaging Techniques
- Ion-surface interactions and analysis
- Microstructure and mechanical properties
- Magnetic Properties of Alloys
- Laser-Matter Interactions and Applications
- Metallic Glasses and Amorphous Alloys
- Advanced Memory and Neural Computing
- Semiconductor materials and devices
- Topological Materials and Phenomena
- Semiconductor materials and interfaces
- Fullerene Chemistry and Applications
- Advanced Condensed Matter Physics
Spintronique et Technologie des Composants
2020-2025
Université Grenoble Alpes
2012-2025
CEA Grenoble
2007-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2007-2024
Centre National de la Recherche Scientifique
2012-2024
Institut polytechnique de Grenoble
2012-2024
Centre d’Élaboration de Matériaux et d’Études Structurales
2012-2022
Imagerie par Résonance Magnétique Médicale et Multi-Modalités
2014-2022
Université Toulouse III - Paul Sabatier
2010-2022
Université de Toulouse
2010-2020
Magnetic skyrmions are topological spin textures which envisioned as nanometer scale information carriers in magnetic memory and logic devices. The recent demonstrations of room temperature their current induced manipulation ultrathin films were first steps toward the realization such However, important challenges remain regarding electrical detection low-power nucleation skyrmions, required for read write operations. Here, we demonstrate, using operando microscopy experiments, a single...
Focused Electron Beam Induced Deposition (FEBID) for magnetic tip fabrication is presented in this work as an alternative to conventional sputtering-based Magnetic Force Microscopy (MFM) tips. FEBID enables the growth of a high-aspect-ratio nanorod with customized geometry and composition overcome key technical limitations MFM probes currently on market. The biggest advantage these tips, comparison CoCr coated pyramidal probes, lies capability creating sharp ends, nearly 10 nm diameter,...
Topology is a powerful tool for categorizing magnetization textures by defining topological index in both two-dimensional (2D) systems, such as thin films or curved surfaces, and 3D bulk systems. In the emerging field of nanomagnetism, volume surface numbers must be considered, requiring identification proper global invariant to support categorization. Here we consider domain walls cylindrical nanowires an excellent playground nanomagnetic excited charge current, that generates Œrsted field....
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Advanced nanofabrication exploiting e-beam lithography has been used to prepare nanocomposites consisting of periodic arrays soft magnetic FeCo-based nano-inclusions variable dimensions, embedded in a hard FePt matrix. Nanocomposites with non-magnetic (Pt) inclusions and single phase microstructures were prepared as reference samples. The formation Kirkendall voids the soft-in-hard nanocomposites, because annealing-induced diffusion, identified through high resolution imaging chemical...
We present an experiment studying the interaction of a strongly focused 25 fs laser pulse with tungsten nanotip, investigating different regimes laser-induced electron emission. study dependence yield respect to static electric field applied tip. Photoelectron spectra are recorded using retarding spectrometer and peaks separated by photon energy observed 45 % contrast. They clear signature above threshold photoemission (ATP), confirmed extensive spectrally resolved studies power dependence....
While magnetic hysteresis usually considers domains, the switching of core vortices has recently become an active topic. We considered Bloch domain walls, which are known to display at surface thin films flux-closure features called N\'eel caps. demonstrated controlled these caps under a field, occurring via propagation vortex. For this we states in elongated micron-sized dots, so that only central wall can be addressed, while domains remain unaffected.
Off-axis electron holography was used to observe and quantify the magnetic microstructure of a perpendicular anisotropic (PMA) recording media. Thin foils PMA materials exhibit an interesting up down domain configuration. These domains are found be very stable were observed at same time with their stray field, closing flux in vacuum. The moment can thus determined locally volume as small few tens cubic nanometers.
Dimensionality cross-over is a classical topic in physics. Surprisingly it has not been searched micromagnetism, which deals with objects such as domain walls (2D) and vortices (1D). We predict by simulation second-order transition between these two objects, the wall length Landau parameter. This was conrmed experimentally based on micron-sized ux-closure dots.
Graphene-based carbon micro-/nano-cones were prepared by depositing pyrolytic onto individual nanotubes as supports using a specific chemical vapor deposition process. They investigated means of high-resolution scanning electron microscopy, low-voltage aberration-corrected transmission Raman spectroscopy, and molecular dynamics modeling. While the graphenes confirmed to be perfect, cone texture was determined preferably scroll-like, with scroll turns being parallel axis. Correspondingly,...
Topological insulators (TIs) hold great promise for new spin-related phenomena and applications thanks to the spin texture of their surface states. However, a versatile platform allowing exploitation these assets is still lacking due difficult integration materials with mainstream Si-based technology. Here, we exploit germanium as substrate growth ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$, prototypical TI. We probe properties ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$/Ge pristine interface by...
The metal-oxide-semiconductor (MOS) capacitor is one of the fundamental electrical components used in integrated circuits. While much effort currently being made to integrate new dielectric or ferroelectric materials, capacitors silicon dioxide on remain most prevalent. It perhaps surprising therefore that electric field within such a has never been measured, mapped out, at nanoscale. Here we present results from operando electron holography experiments showing potential across working MOS...
Speed and reliability of magnetic domain wall (DW) motion are key parameters that must be controlled to realize the full potential DW-based devices for logic memory applications. A major hindrance this is extrinsic DW pinning at specific sites related shape material defects, which may present even if sample synthesis well controlled. Understanding origin reducing it especially desirable in electrochemically deposited cylindrical nanowires (NWs), measurements fascinating physics predicted by...
Perpendicular shape anisotropy (PSA) offers a practical solution to downscale spin-transfer torque magnetoresistive random-access memory (STT-MRAM) beyond the sub-20 nm technology node while retaining thermal stability. However, our understanding of thermomagnetic behavior PSA-STT-MRAM is often indirect, relying on magnetoresistance measurements and micromagnetic modeling. Here, magnetism NiFe nanopillar investigated using off-axis electron holography, providing spatially resolved magnetic...
The structure of domain walls delimiting magnetic bubbles in L10 FePd thin layers is described on the basis Lorentz transmission electron microscopy (LTEM) and multiscale simulations. Images obtained by high resolution LTEM show existence magnetization reversal areas inside walls, called vertical Bloch lines (VBLs). Combining these observations simulations various geometries, we can identify VBLs, notably presence or not singularities.
We probe magnetic domain walls in cylindrical soft nanowires using electron holography. detail the modelling of expected contrast for both transverse and Bloch point provide comparison with experimental observations performed on NiCo nanowires, involving also electrostatic contribution to holography map. This allows fast determination wall type without need uneasy time-consuming removal contribution. Finally, we describe implement a new efficient algorithm calculating contrast.
A dedicated transmission electron microscope sample holder has been used to study in situ the cold-field emission process of carbon cone nanotips (CCnTs). We show that when using a CCnT instead Au plate-anode, standard deviation current noise can be decreased from 10 nA range 1 under vacuum conditions 10−5 Pa. This shows strong influence anode on noise.
We present an electron holography experiment enabling the local and quantitative study of magnetic properties in tunnel junction. The junction was fully characterized during switching process each possible configuration highlighted with induction maps. No coupling found between two layers. plot a hysteresis loop that compared magnetometry measurement at macroscopic scale confirming validity method.