A5031830356- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Advanced Condensed Matter Physics
- Multiferroics and related materials
- Semiconductor materials and devices
- Ferroelectric and Piezoelectric Materials
- Magnetic Properties and Synthesis of Ferrites
- Advanced Memory and Neural Computing
- Magnetic properties of thin films
- Integrated Circuits and Semiconductor Failure Analysis
- Gas Sensing Nanomaterials and Sensors
- Transition Metal Oxide Nanomaterials
- Force Microscopy Techniques and Applications
- Neuroscience and Neural Engineering
- Magnetic Properties and Applications
- Ferroelectric and Negative Capacitance Devices
- Photoreceptor and optogenetics research
- Photonic and Optical Devices
- Electronic Packaging and Soldering Technologies
- Near-Field Optical Microscopy
- Copper-based nanomaterials and applications
- Chalcogenide Semiconductor Thin Films
- 3D IC and TSV technologies
- Physics of Superconductivity and Magnetism
Laboratoire de Cristallographie et Sciences des Matériaux
2016-2025
Université de Caen Normandie
2009-2025
Normandie Université
2016-2025
Centre National de la Recherche Scientifique
2016-2025
École Nationale Supérieure d'Ingénieurs de Caen
2016-2025
Murata (United States)
2021
University of Augsburg
2011
Indian Institute of Technology Madras
2010
Laboratoire de physique de la matière condensée
2009
Office National d'Études et de Recherches Aérospatiales
2006-2007
Ultrathin layers of the versatile spinel oxide NiFe2O4 can be conductive or insulating depending on growth conditions. Conductive (NFO) electrodes are inserted into conventional magnetic tunnel junctions containing La2/3Sr1/3MnO3/SrTiO3 (LMSO/STO) bilayers, and ferrimagnetic used as barriers to define a spin filter (see figure). The ability such heterostructures highly spin-polarize electrons injected from non-magnetic electrode is demonstrated.
The magnetic exchange between epitaxial thin films of the multiferroic (antiferromagnetic and ferroelectric) hexagonal YMnO3 oxide a soft ferromagnetic (FM) layer is used to couple response FM state antiferromagnetic one. We will show that biasing ferroelectric by an electric field allows control bias subsequently magnetotransport properties layer. This finding may contribute paving way towards new generation electric-field controlled spintronic devices.
We report experiments of spin-filtering through ultrathin insulating layers the high Curie temperature ferrimagnetic oxide NiFe2O4 (NFO). The efficiency electrons tunneling from a gold electrode NFO is analyzed with counter-electrode La2∕3Sr1∕3MnO3 (LSMO). measure tunnel magnetoresistance 40%–50% when configuration magnetizations and LSMO goes parallel to antiparallel. This value corresponds up 22% by barrier. discuss sign dependence spin-filter effect argue that our results show potential...
Bulk $\mathrm{Ni}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$ is an insulating ferrimagnet. Here, we report on the epitaxial growth of spinel ultrathin films onto $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ single crystals. We will show that---under appropriate conditions---epitaxial stabilization leads to formation a phase with magnetic and electrical properties that radically differ from those bulk material: enhanced moment $({M}_{S})$---about 250% larger---and metallic character. A systematic study...
The effect of biaxial strain on the oxygen octahedra rotations in a LaVO${}_{3}$ thin film is investigated using synchrotron radiation. First, we find that adopts distorted orthorhombic structure under compressive stress induced by SrTiO${}_{3}$ substrate. Second, separate contribution to superstructure peaks arising from cation displacement and VO${}_{6}$ order quantify rotation angles. Finally, an original ${a}^{\ensuremath{-}}{a}^{+}{c}^{\ensuremath{-}}$ tilt system, which imposed These...
This paper reports on the study of series tungsten doped Ni0.5Zn0.5WxFe2−xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) ferrites synthesized by a co-precipitation scheme. The crystallite size varies from 62 to 49 nm and scanning electron microscope (SEM) images show spinel cubic structure powder sample. Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF) confirms presence Ni, Zn, W Fe elements in prepared samples. specific surface areas Ni0.5Zn0.5W0.2Fe1.8O4, Ni0.5Zn0.5W0.4Fe1.6O4...
The integration of perovskite oxides onto flexible substrates has witnessed significant advancements owing to the development an epitaxial lift-off technique utilizing a Sr3Al2O6 sacrificial layer. However, is susceptible instability in both air and high-temperature oxygen atmospheres, potentially leading degradation during growth functional oxide In this study, we investigate use oxygen-deficient La0.7Sr0.3MnO3 as capping layer, demonstrate its ability stabilize films ambient air. We...
Uniaxial magnetic anisotropy has been observed in La0.7Sr0.3MnO3 thin films grown on top of multiferroic BiFeO3 with ferroelectric stripe domains (see Figure). The easy axis correlates the domains. A possible spin coupling model at La0.7Sr0.3MnO3/BiFeO3 interface is established between ferromagnetic and antiferromagnetic orders to explain this phenomenon.
Based on the Hubbard model of strongly correlated systems, a reduction in bandwidth electrons can yield substantial change properties material. One method to modify is geometrically confined doping, i.e., introduction (thin) dopant layer In this Rapid Communication, magnetic ${\text{LaVO}}_{3}/{\text{SrVO}}_{3}$ superlattices, which doping produced by one monolayer thick ${\text{SrVO}}_{3}$ film, are presented. contrast solid solution...
Abstract The vanadate SrVO 3 is a transparent conductor perovskite with optical and electrical properties competing those of the most‐used indium tin oxide material. Although its charge density comparable to that metals, shows plasma frequency below visible range due strong electronic correlations characterizing transport in this material enhancing effective mass. Therefore, well‐known interplay between structure strongly correlated systems can be used such tune properties, as also depends...
Exchange bias, HE, and coercivity, HC, of antiferromagnetic (AFM)/ferromagnetic bilayers can be adjusted, after deposition, at temperatures below the Néel temperature AFM by subjecting samples to large pulsed fields (in excess HPulse=550 kOe). The efficiency process depends on system direction applied field with respect unidirectional anisotropy direction. Textured (111) Fe19Ni81/Fe50Mn50 show an HE reduction a HC increase when pulse is antiparallel anisotropy, while they only exhibit in...
It has been shown recently that the perovskite oxide SrVO3 is a transparent conductor with optical and electrical properties outreaching those of most used material indium tin (ITO). These properties, observed in crystalline phase, imply strong potential for use as lower cost alternative to ITO, but possible integration this actual electronic devices still an open question. One approaches materials amorphous thin films, allowing low thermal budgets preserve performances device. Therefore,...
SrVO3 is a strongly correlated metal which has been highly studied in recent years due to its optical and electrical properties, makes it promising transparent conducting oxide (TCO). By investigating optimizing these interesting might be able replace the future indium–tin oxide, most commonly used TCO at current time but suffers from resource depletion. In this study, films of about 30 nm were grown by reactive sputtering Sr2V2O7 target onto Si substrates, both with without TiO2 buffer...
Due to the expansion of defects like single Shockley-type Stacking Faults inside SiC epitaxial drift layer, during high current stress, classical MOSFETs can be victims degradation their electrical characteristics. The introduction an buffer layer between substrate and n- epilayer, called recombination-enhancing was shown avoid this degradation. In paper, TCAD simulations behavior such a commercial MOSFET device with varying thickness are studied, indicating only small modifications These...
Self-organized pyramidal structures (quadratic or hut-cluster type) of ferrimagnetic spinel ${\text{CoCr}}_{2}{\mathrm{O}}_{4}$ (CCO) are grown by deposition from vapor phase on ${\text{MgAl}}_{2}{\mathrm{O}}_{4}(001)$ substrates. The surfaces the structures, forming an angle $\ensuremath{\Theta}\ensuremath{\approx}50--55\ifmmode^\circ\else\textdegree\fi{}$ with (001) surface, identified as ${111}$ facets, so pyramids can be considered true three-dimensional objects. Important...
A spin filter is a type of magnetic tunnel junction in which only one the electrodes and insulating barrier ferro- or ferrimagnetic. We report on spin-dependent transport measurements their theoretical analysis epitaxial filters integrating high-Curie-temperature ferrimagnetic spinel $\mathrm{Ni}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$, with half-metallic ${\mathrm{La}}_{2∕3}{\mathrm{Sr}}_{1∕3}\mathrm{Mn}{\mathrm{O}}_{3}$ Au electrodes. positive magnetoresonance up to $\ensuremath{\sim}50%$...
We exploit the magnetic interlayer coupling in La0.7Sr0.3MnO3/SrRuO3 superlattices to realize a crossover between inverse and conventional entropy changes. Our data reveal strong anisotropic nature of magnetocaloric effect due anisotropy superlattice. Therefore, artificial built from ferromagnetic materials that can be used alter structure as well anisotropy, could also utilized for tuning properties, which may open constructive approach refrigeration applications.
Ferroelectric domains were investigated using piezoresponse force microscopy in superlattices composed of multiferroic BiFeO3 and SrTiO3 layers. Compared to single thin films, a reduction the size suppression in-plane orientation are observed superlattice (BiFeO3)4(SrTiO3)8, suggesting constrained ferroelectric domain along out-of-plane ⟨001⟩ direction. Such modification BiFeO3-based heterostructures could play vital role on engineering wall mediated functional properties necessary for...
High quality amorphous nanolaminates by means of alternate Al2O3 and TiO2 oxide sublayers were grown with atomic scale thickness control pulsed laser deposition. A giant dielectric constant (>10 000), strongly enhanced compared to the value either or their solid solution, was observed. The dependence loss on individual layer each constituting materials investigated between 0.3 nm 1 nm, in order understand prevailing mechanisms allow for an optimization performances. An impedance study...
We report on the growth and functional characterization of epitaxial thin films multiferroic YMnO3. show that using Pt as a seed layer SrTiO3(111) substrates, YMnO3 (0001) textured are obtained. An atomic force microscope has been used to polarize electric domains revealing ferroelectric nature film. When Permalloy is grown top YMnO3(0001) film, clear indications exchange bias enhanced coercivity observed at low temperature. The observation coexisting antiferromagnetism electrical...