A5025377536- Rare-earth and actinide compounds
- Magnetic Properties of Alloys
- Advanced Chemical Physics Studies
- Magnetic and transport properties of perovskites and related materials
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Topological Materials and Phenomena
- Graphene research and applications
- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Inorganic Chemistry and Materials
- X-ray Diffraction in Crystallography
- High-pressure geophysics and materials
- Magnetic Properties and Applications
- Surface and Thin Film Phenomena
- Crystallization and Solubility Studies
- Heusler alloys: electronic and magnetic properties
- ZnO doping and properties
- Nuclear Materials and Properties
- Theoretical and Computational Physics
- Quantum and electron transport phenomena
- Electron and X-Ray Spectroscopy Techniques
- Magnetism in coordination complexes
- Advanced Physical and Chemical Molecular Interactions
- Perovskite Materials and Applications
Leibniz Institute for Solid State and Materials Research
2014-2023
TU Dresden
1999-2023
CEA Paris-Saclay
2015-2019
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015-2019
Université Paris-Saclay
2019
Laboratoire Interactions, Dynamiques et Lasers
2019
Center for Systems Biology Dresden
2017
Service de Physique de l'État Condensé
2015
Institut Rayonnement-Matière de Saclay
2015
CY Cergy Paris Université
2006-2015
A comparison of DFT methods Density functional theory (DFT) is now routinely used for simulating material properties. Many software packages are available, which makes it challenging to know the best use a specific calculation. Lejaeghere et al. compared calculated values equation states 71 elemental crystals from 15 different widely codes employing 40 potentials (see Perspective by Skylaris). Although there were variations in values, most recent and converged toward single value, with...
Because of the outstanding high theoretical specific energy density 2600 Wh kg–1, lithium–sulfur (Li–S) battery is regarded as a promising candidate for post lithium-ion systems eligible to meet forthcoming market requirements. However, its commercialization on large scale thwarted by fast capacity fading caused Achilles' heel Li–S systems: polysulfide shuttle. Here, we merge physical features carbon-coated separators and unique chemical properties N S codoped mesoporous carbon create...
Engineering intramolecular exchange interactions between magnetic metal atoms is a ubiquitous strategy for designing molecular magnets. For lanthanides, the localized nature of 4f electrons usually results in weak coupling. Mediating lanthanide ions via radical bridges fruitful towards stronger In this work we explore limiting case when role bridge played by single unpaired electron. We synthesize an array air-stable Ln2@C80(CH2Ph) dimetallofullerenes (Ln2 = Y2, Gd2, Tb2, Dy2, Ho2, Er2, TbY,...
Combinations of non-trivial band topology and long-range magnetic order hold promise for realizations novel spintronic phenomena, such as the quantum anomalous Hall effect topological magnetoelectric effect. Following theoretical advances material candidates are emerging. Yet, a compound with band-inverted electronic structure an intrinsic net magnetization remains unrealized. MnBi$_2$Te$_4$ is candidate first antiferromagnetic insulator progenitor modular (Bi$_2$Te$_3$)$_n$(MnBi$_2$Te$_4$)...
The band structure theory of magnetism in 3d-4f compounds is reviewed. Among the open-shell electrons, a hierarchy interactions present which governs intrinsic magnetic properties these materials. Density functional (DFT) an appropriate tool to describe and quantitatively investigate both ground state model interaction parameters, are necessary calculate temperature-dependent behaviour. cornerstones DFT explicitly sketched, as well recent developments needed cope with treatment localized 4f...
Ab initio calculations are presented for the giant magnetoresistance (GMR) of Fe/Cr multilayers. The electronic structure superlattices is calculated within spin density functional theory. spin-dependent bulk impurity scattering treated in a fully quantum mechanical way using Green function formalism. transport described quasiclassically. suggest that GMR thin multilayers mainly determined by layered system. Spin-dependent can reduce, increase, or invert effect.
It is demonstrated by means of density functional and ab-initio quantum chemical calculations, that transition metal - carbon systems have the potential to enhance presently achievable area magnetic recording three orders magnitude. As a model system, Co_2-benzene with diameter 0.5 nm investigated. shows anisotropy in order 0.1 eV per molecule, large enough store permanently one bit information at temperatures considerably larger than 4 K. A similar performance can be expected, if cobalt...
The maximum isothermal entropy change in a magnetic refrigerant with second-order phase transition is shown to depend on applied field $H$ as follows: $(\ensuremath{-}\ensuremath{\Delta}S){}_{\mathrm{max}}$ $=$ $A$($H$ $+$ ${H}_{0}$)${}^{2/3}$ -- ${\mathit{AH}}_{0}^{2/3}$ $\mathit{BH}$${}^{4/3}$. Here $A$ and $B$ are intrinsic parameters of the cooling material ${H}_{0}$ an extrinsic parameter determined by purity homogeneity sample. This theoretical prediction confirmed measurements...
We report a comprehensive experimental investigation on the magnetic anisotropy in bulk single crystals of ${\mathrm{Cr}}_{2}{\mathrm{Ge}}_{2}{\mathrm{Te}}_{6}$, quasi-two-dimensional ferromagnet belonging to family layered transition metal trichalcogenides that have recently attracted great deal interest with regard fundamental and applied aspects two-dimensional magnetism. For this purpose electron spin resonance (ESR) ferromagnetic (FMR) measurements been carried out over wide frequency...
The ferromagnetic semiconductor $\mathrm{B}{\mathrm{a}}_{2}\mathrm{NiOs}{\mathrm{O}}_{6}$ (${T}_{\mathrm{mag}}\ensuremath{\sim}100\phantom{\rule{0.16em}{0ex}}\mathrm{K}$) was synthesized at 6 GPa and 1500 \ifmmode^\circ\else\textdegree\fi{}C. It crystallizes into a double perovskite structure [$Fm\ensuremath{-}3m$; $a=8.0428(1)\phantom{\rule{0.16em}{0ex}}\AA{}$], where the $\mathrm{N}{\mathrm{i}}^{2+}$ $\mathrm{O}{\mathrm{s}}^{6+}$ ions are perfectly ordered $B$ site. We show that spin-orbit...
Dirac-like dispersion in topological surface states is strongly perturbed by hybridization with valence-band for Bi${}_{2}$Te${}_{3}$-terminated surfaces, but remains preserved MnBi${}_{2}$Te${}_{4}$-terminated surfaces.
Computer experiments have been performed to study the single-particle density of states, g(E), in Coulomb gap. This gap occurs disordered insulating systems as an effect long-range tail interaction. In order compare these numerical results with analytical theory on a broader energy scale than previous authors, very large samples considered, up 40 000 and 125 sites for dimensions d=2 3, respectively. Special algorithms developed this aim. Our contradict from literature two main points: As...
The effect of spin-orbit coupling and orbital polarization (OP) corrections on the spin magnetism full Heusler alloys is investigated by means local spin-density calculations. It demonstrated that OP are needed to explain experimental moments ${M}_{l}$. Model calculations employing one ligand field parameter yield correct order magnitude ${M}_{l}$, but do not account for its quantitative composition dependence. Spin-orbit reduces degree density states at Fermi level a few percent. We provide...
Strained coherent film growth is commonly either limited to ultrathin films or low strains. Here, we present an approach achieve high strains in thicker films, by using materials with inherent structural instabilities. As example, 50 nm thick epitaxial of the Fe70Pd30 magnetic shape memory alloy are examined. on various substrates allows us adjust tetragonal distortion from c/a{bct}=1.09 1.39, covering most Bain transformation path fcc bcc crystal structure. Magnetometry and x-ray circular...
In a recent experiment, Weisheit et al (2007 Science 315 349) demonstrated that the coercivity of thin L10 FePt and FePd films can be modified by external electric field in an electrochemical environment. Here, this observation is confirmed density functional calculations for intrinsic magnetic anisotropy. The origin effect clarified means general simple method to simulate charged metal surfaces. It predicted CoPt much more susceptible than films.
We have undertaken theoretical studies of spin and orbital magnetic moments as well anisotropy energies for ${M}_{13}$ $(M=\text{Fe},\text{Co},\text{Ni})$ ${M}_{13}{\text{Pt}}_{n}$ $(n=3,4,5,20)$ clusters including the spin-orbit coupling in framework density functional theory. For all considered we find tendencies small structural distortions which can be characterized by either Jahn-Teller (JT) or Mackay transformations (MT). The energy (MAE) along with are calculated icosahedral...
The magnetic and structural properties of Fe–Pt nanocomposites related idealized structures have been investigated by a combination experimental theoretical techniques. dependence magnetocrystalline anisotropy (MCA) L10 FePt on the ratio tetragonal lattice parameters, c/a, has calculated with relativistic version full potential local orbital method, assuming complete chemical order fixed unit-cell volume. It found that well known distortion in this phase relatively small influence MCA...
From a first-principles density-functional (DF) calculation of the charge distribution all crystal-field (CF) parameters for 4f states at Sm site in ${\mathrm{SmCo}}_{5}$ have been evaluated. The is based on an optimized linear combination atomic orbitals scheme conduction-electron magnetism and ``open core shell'' treatment localized moments. Real-space integrations are used to evaluate both on-site lattice contributions CF parameters. It explicitly shown that there no justification...