A5103085016- Advanced Condensed Matter Physics
- Iron oxide chemistry and applications
- Multiferroics and related materials
- Magnetic and transport properties of perovskites and related materials
- Rare-earth and actinide compounds
- Characterization and Applications of Magnetic Nanoparticles
- Magnetic properties of thin films
- Laser-Ablation Synthesis of Nanoparticles
- Magnetic Properties and Synthesis of Ferrites
- Magnetic Properties of Alloys
- Physics of Superconductivity and Magnetism
- Catalytic Processes in Materials Science
- Diamond and Carbon-based Materials Research
- Microfluidic and Capillary Electrophoresis Applications
- Ferroelectric and Piezoelectric Materials
- Iron-based superconductors research
- Nuclear materials and radiation effects
- Microfluidic and Bio-sensing Technologies
- Electrowetting and Microfluidic Technologies
- Nanocluster Synthesis and Applications
- Mesoporous Materials and Catalysis
- Geophysical and Geoelectrical Methods
- Thermodynamic and Structural Properties of Metals and Alloys
- Metal Extraction and Bioleaching
- Concrete and Cement Materials Research
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2010-2022
CEA Paris-Saclay
2010-2022
Service de Physique de l'État Condensé
2007-2022
Centre National de la Recherche Scientifique
2012-2022
Université Paris-Saclay
2016-2022
Institut Rayonnement-Matière de Saclay
2009-2018
Direction des énergies
2005-2014
DSM (Netherlands)
2004
Sorbonne Université
2004
From magnetic, specific heat, $^{170}\mathrm{Yb}$ M\"ossbauer effect, neutron diffraction, and muon spin relaxation measurements on polycrystalline ${\mathrm{Yb}}_{2}{\mathrm{Sn}}_{2}{\mathrm{O}}_{7}$, we show that below the first order transition at 0.15 K all of ${\mathrm{Yb}}^{3+}$ ions are long-range magnetically ordered each has a moment $1.1{\ensuremath{\mu}}_{\mathrm{B}}$ which lies $\ensuremath{\simeq}10\ifmmode^\circ\else\textdegree\fi{}$ to common fourfold cubic axis. The four...
The dynamical magnetic correlations in ${\mathrm{Tb}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$ have been investigated using polarized inelastic neutron scattering. Dispersive excitations are observed, emerging from pinch points reciprocal space and characterized by an anisotropic spectral weight. Anomalies the crystal field phonon excitation spectrum at Brillouin zone centers also reported. These findings suggest that Coulomb phases, although they present a disordered ground state with dipolar...
Here, it is shown that binary superlattices of Co/Ag nanocrystals with the same size, surface coating, differing by their type crystallinity are governed Co-Co magnetic interactions. By using 9 nm amorphous-phase Co and 4 polycrystalline Ag at 25 °C, triangle-shaped NaCl-type nanocrystal produced driven entropic force, maximizing packing density. contrast, ferromagnetic single domain (hcp) instead Co, dodecagonal quasicrystalline order obtained, together less-packed phases such as CoAg13...
We compare here exchange bias (EB) properties of chemically synthesized core–shell nanoparticles (NPs), based either on a core soft ferrite (MnFe2O4) or hard (CoFe2O4) protected by maghemite shell (γ-Fe2O3). These NPs dispersed in acidic solutions are electrostatically stabilized, yielding to stable colloidal dispersions with strong interparticle repulsion and negligible dipolar interactions the probed range temperatures. Field cooled (FC) magnetic hysteresis loops non-textured frozen (with...
Biocompatible magnetic dispersions have been prepared from γ-Fe2O3 nanoparticles (5 nm) synthesized by continuous laser pyrolysis of Fe(CO)5 vapours. The feasibility using these as resonance imaging (MRI) contrast agents has analysed in terms chemical structure, properties, 1H NMR relaxation times and biokinetics. were dispersed a strong alkaline solution the presence dextran, yielding stable colloids single step. consist particle-aggregates 25 nm diameter measured transmission electron...
Maghemite nanocrystals, deposited by slow evaporation on HOPG (highly oriented pyrolytic graphite) substrate, form mesoscopic structures which strongly depend the nanocrystal coating. When coating consists of citrate ions and octanoic acid, tubelike are formed when deposition process takes place under an applied magnetic field. Conversely, dense films nanocrystals coated with propanoic acid dodecanoic acid. The behaviors markedly differ organization attributed to change in anisotropy...
We have studied the MnGe chiral magnet below ${T}_{\text{N}}=170$ K, by magnetic measurements, M\"ossbauer spectroscopy, and neutron diffraction at ambient under nonhydrostatic pressure. At pressure, we observe coexistence of two phases belonging to same crystal phase in a large temperature range (down 100 K) ${T}_{\mathrm{N}}$: ferromagnetically correlated rapidly fluctuating spins coexist with frozen involved helical order. Applying uniaxial pressure component induces strong texture, where...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLangmuir-Blodgett Films of Spin Transition Iron(II) Metalloorganic Polymers. 1. Complexes Octadecyl-1,2,4-triazoleF. Armand, C. Badoux, P. Bonville, A. Ruaudel-Teixier, and O. KahnCite this: Langmuir 1995, 11, 9, 3467–3472Publication Date (Print):September 1, 1995Publication History Published online1 May 2002Published inissue 1 September 1995https://pubs.acs.org/doi/10.1021/la00009a032https://doi.org/10.1021/la00009a032research-articleACS...
We report the discovery of two consecutive, pressure driven magnetic instabilities in ${\mathrm{Yb}}_{2}{\mathrm{Pd}}_{2}\mathrm{Sn}$. They emerge a non-Fermi liquid environment at initial and final point dome-like, single phase pressures ${\mathrm{p}}_{\mathrm{c}1}\ensuremath{\approx}1$ GPa ${\mathrm{p}}_{\mathrm{c}2}\ensuremath{\approx}4$ GPa. This singular behavior Yb compounds is supposed to result from mutually competing, modified energy scales, which case...
Inspired by metallic alloys in atomic solids, two distinct nanoparticles are used, considered as “artificial metal atoms,” to engineer ordered binary nanoparticle at the mesoscale, called supracrystals. Here, ferromagnetic 7.2 nm Co used large “A” site particles, while either 4.6 or nonmagnetic 4.0 Ag small “B” particles fabricate long‐range supracrystals with a stoichiometry of AB 2 and 13 . The interparticle distances between within Co/Ag can be tuned control crystal structure from (CoAg )...
We present here a neutron diffraction study, both in zero field and as function of magnetic field, the structure tetragonal intermetallic ${\mathrm{EuNiGe}}_{3}$ on single crystalline sample. This material is known to undergo cascade transitions, first at 13.2 K towards an incommensurate modulated structure, then 10.5 antiferromagnetic structure. show that low-temperature phase presents spiral moment arrangement with wave vector $\mathbit{k}=(\frac{1}{4},\ensuremath{\delta},0)$. For applied...
We present a model which accounts for the high-field magnetization at very low temperature in frustrated pyrochlore compound Er2Ti2O7. In Er2Ti2O7, Er(3+) ion has planar crystal field anisotropy and material undergoes transition to antiferromagnetism TN = 1.2 K. Our is mean-field self-consistent calculation involving four rare earth sites of tetrahedron, building unit lattice. It includes full Hamiltonian, infinite range dipolar interaction anisotropic nearest neighbour exchange described by...
Assembly of nanoparticles into supracrystals provides a class materials with interesting optical and magnetic properties. However, are mostly obtained from hydrophobic particles therefore cannot be manipulated in aqueous systems, limiting their range applications. Here, we show that hydrophobic-shaped self-assembled 8.2 nm cobalt can dispersed water by coating the lipid vesicles. A careful characterization these composite objects insights structure at different length scales. This composite,...
ZnFe2O4 nanoparticles with a mean size ranging from 3 nm to 10 nm, have been prepared using the solvothermal method. The TEM images reveal narrow particle distribution for all samples. Bulk magnetic measurements indicate superparamagnetic behaviour blocking temperature (TB) that increases K 22 upon increasing size. At temperatures lower than TB are in "frozen" regime and coercive field changes 145 Oe 220 sizes nm. On heating, Mössbauer spectroscopy data show progressive crossover quadrupolar...
Inexpensive simple medical devices allowing fast and reliable counting of whole cells are interest for diagnosis treatment monitoring. Magnetic-based labs on a chip one the possibilities currently studied to address this issue. Giant magnetoresistance (GMR) sensors offer both great sensitivity device integrability with microfluidics electronics. When used dynamic system, GMR-based biochips able detect magnetically labeled individual cells. In article, rigorous evaluation main characteristics...
This paper reports original results on the synthesis of Carbon/Nitrogen/Iron-based Oxygen Reduction Reaction (ORR) electrocatalysts by CO2 laser pyrolysis. Precursors consisted two different liquid mixtures containing FeOOH nanoparticles or iron III acetylacetonate as precursors, being fed to reactor an aerosol droplets. Carbon and nitrogen were brought pyridine a mixture ethanol depending precursor involved. The use ammonia energy transfer agent also provided potential source. For each...
The structural evolution of iron during cement paste degradation is studied. An increased concentration has been observed in the surface layer formed when comes into contact with an aggressive solution. While C 4 AF and 3 (A, F)SH are little affected by leaching, calcium silicate hydrates (CSH) become richer trivalent on surface. latter replaces labile non-labile structure, form being predominant.