A5053837387- Rare-earth and actinide compounds
- Magnetic Properties of Alloys
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Thermodynamic and Structural Properties of Metals and Alloys
- Physics of Superconductivity and Magnetism
- High-pressure geophysics and materials
- Iron-based superconductors research
- Nuclear Physics and Applications
- Advanced Materials Characterization Techniques
- Boron and Carbon Nanomaterials Research
- Thermal Expansion and Ionic Conductivity
- Nuclear Materials and Properties
- Superconductivity in MgB2 and Alloys
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Chemical Physics Studies
- Magnetic properties of thin films
- Crystal Structures and Properties
- Atomic and Subatomic Physics Research
- Solid-state spectroscopy and crystallography
- Advanced Thermoelectric Materials and Devices
- Nuclear physics research studies
- Inorganic Chemistry and Materials
- Fusion materials and technologies
- Intermetallics and Advanced Alloy Properties
Immanuel Kant Baltic Federal University
2016-2023
Institute for Nuclear Research
2010-2020
Petersburg Nuclear Physics Institute
2017
Kurchatov Institute
1999-2014
Russian Academy of Sciences
2009-2014
Moscow Engineering Physics Institute
2011-2014
Institute of Engineering Physics
2012
All-Russian Scientific Research Institute of Technical Physics
2006-2009
Technical University of Munich
2002-2007
Paul Scherrer Institute
2000-2005
The first ab initio calculations using ultrasoft pseudopotentials within the local-density approximation in superconducting ${\text{ZrB}}_{12}$ are reported, together with an inelastic neutron scattering study of its lattice dynamics. As previously studied rare-earth dodecaborides, phonon spectra mainly determined by vibrations rigid boron network whereas Zr atoms have a quasilocal character and localized narrow energy range around $E\ensuremath{\approx}17\text{ }\text{meV}$. results...
In mixed-valence or heavy-fermion systems, the hybridization between local $f$ orbitals and conduction band states can cause suppression of long-range magnetic order, which competes with strong spin fluctuations. Ce- Yb-based systems have been found to exhibit fascinating physical properties (heavy-fermion superconductivity, non-Fermi-liquid states, etc.) when tuned vicinity quantum critical points by use various external control parameters (temperature, field, chemical composition)....
A quantitative analysis of the crucial characteristics currently used and promising materials for X-ray refractive optics is performed in extended energy range 8–100 keV. According to examined parameters, beryllium material choice compound lenses (CRLs) 8–25 At higher energies use CRLs made diamond cubic phase boron nitride (c-BN) beneficial. It was demonstrated that presence elements fourth (or higher) period has a fatal effect on functional properties even if low- Z dominate compound, like...
We have studied the effect of Lu substitution on spin dynamics Kondo insulator YbB 12 to clarify origin spin-gap response previously observed at low temperature in this material.Inelastic neutron spectra been measured Yb 1-x x B compounds for four concentrations = 0, 0.25, 0.90 and 1.0.The data indicate that disruption coherence sublattice primarily affects narrow peak structure occurring near 15-20 meV pure , whereas gap broad magnetic signal around 38 remain almost unaffected.It is...
The effects of Tm substitution on the dynamical magnetic response Yb${}_{1\ensuremath{-}x}$Tm${}_{x}$B${}_{12}$ $(x=0$, 0.08, 0.15, and 0.75) Lu${}_{0.92}$Tm${}_{0.08}$B${}_{12}$ compounds have been studied using time-of-flight inelastic neutron scattering. Major changes were observed in spectral structure temperature evolution Yb contribution to for a rather low content ions. A sizable influence $R$B${}_{12}$ host (YbB${}_{12}$, as compared LuB${}_{12}$ or pure TmB${}_{12}$) crystal-field...
Conventional magnetic and transport measurements of the melt-grown mixed-valence manganite $({\mathrm{La}}_{0.4}{\mathrm{Eu}}_{0.6}{)}_{0.7}{\mathrm{Pb}}_{0.3}{\mathrm{MnO}}_{3}$ have been supplemented by a resonance study. The experimental data support model two phases coexisting in crystal volume. At temperature ${T}^{*}$, which is well above Curie ${T}_{C}$, ferromagnetic clusters appear sample. These regions possess higher conductivity comparison with paramagnetic background (majority...
The cerium effective valence was investigated by means of CeL3-XANES spectroscopy in some intermediate Ce-based systems with different magnetic ordering mechanisms: CeNi doped Nd, Pr and Gd the temperature range 5–300 K, Ce3Fe17–xMnx intermetallics. dependences obtained are considered within frames generally accepted mechanisms rare-earth ions states. Possible correlations between properties compounds also noted.
The paramagnetic spectral response of the intermediate-valence compound CeNi has been studied by inelastic neutron scattering on isotopically ${(}^{60}\mathrm{Ni})$ enriched single-crystal and powder samples. At low temperature $(T\ensuremath{\sim}10\mathrm{K}),$ no magnetic intensity was found up to an energy $E\ensuremath{\approx}15\mathrm{meV},$ indicating a spin-gap-like response. absence detectable quasielastic in high-resolution time-of-flight spectra provides clear evidence for...
A Pb3Mn7O15 single crystal has been grown by the flux method and studied using x-ray diffraction magnetization measurements. The is hexagonal (P63/mcm space group, Z = 4) exhibits a pronounced layered nature. Along [001] direction (c axis), structure consists of layers edge-sharing MnO6 octahedra. Pairs Mn atoms occupy octahedral sites located between forming 'bridges' along c axis, which link neighboring layers. magnetic properties have investigated ac dc measurements in temperature range...
The 4f electron excitation spectra for a series of Ce1 − xLaxNi compounds with x = 0;0.2;0.5 and 0.8, where transition occurs from intermediate valence to localized state, have been measured at T 12 K by inelastic neutron scattering wide range energy transfer. A qualitative change the magnetic response takes place when hybridization becomes nearly equal crystal field splitting shell. In pure CeNi, gap-like spectrum has observed.
The phonon dispersion relations in MnSi were measured using inelastic neutron scattering. At the same time, calculations of lattice dynamics carried out framework density-functional theory both local-density and generalized gradient approximations. match most modes frequency range up to 40 meV, if they are performed experimental constant. Spin-polarized for ferromagnetic ground states result subtle modifications curves, which further improve description, particular, acoustic branches.
The low-energy phonon modes of the intermediate-valence system CeNi and isostructural reference compound LaNi have been measured at room temperature by inelastic neutron scattering in planes (001) (100). In general, frequencies acoustic lower optical-phonon branches are found to be appreciably CeNi. This effect is especially dramatic for propagating along $a$ $b$ directions. Maximum softening was observed near zone boundary, where it can exceed 20% some branches. These data represent most...
The magnetic spectral response of black-phase mixed-valence Sm0.83Y0.17S has been measured by inelastic neutron scattering on a single crystal. Two peaks are observed in the energy range Sm2+ spin-orbit transition (25-40 meV). Both them exhibit significant dispersion along three main symmetry directions, reminiscent exciton branch found pure divalent SmS. results can be reproduced simple phenomenological model accounting for existence sizeable Sm-Sm exchange interactions, and microscopic...
This work is focused on the fabrication and characterization of a new type composite invar materials combining near-zero thermal expansion functional properties that are important for applications. accomplished through use particles SmB6, an intermediate valence system with negative expansion, embedded in Al matrix. The based SmB6-21 vol% was fabricated by hot pressing characterized XRD, optical/electron microscopy, X-ray computed tomography capacitive dilatometry. study revealed sample...
A new large-scale research center for nano diagnostics and neutron X-Ray studies of nanomaterials is briefly described. This at the Institute Nuclear Research Russian Academy Sciences (INR RAS) based on three specially designed spallation sources driven by primary proton beams. Similar centers basis high flux are created in USA, Japan, Great Britain, Switzerland will be build China EU (Sweden). We discuss instrumentation INR RAS corresponding domains various materials including nano-systems.
We describe neutron inelastic scattering measurements of spin waves in the quasi-two-dimensional antiferromagnet FeTa2O6. The intrinsic wave dispersion for a single domain is deduced from linear theory and used to determine intra-plane exchange coefficients. Almost dispersion-free excitations are observed along c* direction perpendicular magnetic planes. This justifies neglect inter-plane coupling, which merely stabilizes ordered configuration below TN. Spin yields values nearest neighbour...