A5061655843- Rare-earth and actinide compounds
- Magnetic Properties of Alloys
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Advanced Chemical Physics Studies
- Superconductivity in MgB2 and Alloys
- Physics of Superconductivity and Magnetism
- Boron and Carbon Nanomaterials Research
- High-pressure geophysics and materials
- Advanced Condensed Matter Physics
- Inorganic Chemistry and Materials
- Graphene research and applications
- Metallurgical and Alloy Processes
- Intermetallics and Advanced Alloy Properties
- Surface and Thin Film Phenomena
- Quasicrystal Structures and Properties
- Heusler alloys: electronic and magnetic properties
- Corporate Taxation and Avoidance
- Semiconductor Quantum Structures and Devices
- Carbon Nanotubes in Composites
- Multiferroics and related materials
- Thermodynamic and Structural Properties of Metals and Alloys
- Diamond and Carbon-based Materials Research
- Quantum and electron transport phenomena
- Inorganic Fluorides and Related Compounds
National Academy of Sciences of Ukraine
2014-2024
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine
2014-2024
V.E. Lashkaryov Institute of Semiconductor Physics
2012
Uppsala University
1997-2003
Flanders Marine Institute
1997
National Institute of Technology, Kure College
1997
Physicotechnical Institute
1980-1995
Physico-Technical Institute
1986-1991
Ab initio band structure calculations are carried out for the higher borides MB6 and MB12. High-precision measurements of elastic constants performed compounds ZrB12, HoB12, ErB12, TmB12, LuB12, YB6 LaB6 at low temperatures. The bulk properties analyzed on basis calculated equations states balanced crystal orbital overlap populations. Our indicate that hexaborides with divalent metals, CaB6, SrB6, BaB6, YbB6, semiconductors small energy gaps. metallic trivalent M atoms found to possess...
The volume dependent electronic structure of the spinel-type lithium manganese oxides ${\mathrm{Li}}_{x}{\mathrm{Mn}}_{2}{\mathrm{O}}_{4},$ $x=0,0.5,1,$ is studied ab initio by employing a full-potential method. structure, total energies, open-circuit voltage, and magnetic moments were obtained for various spin configurations ${\mathrm{Li}}_{x}{\mathrm{Mn}}_{2}{\mathrm{O}}_{4}$ in cubic spinel low-temperature orthorhombic structure. effect ordering on band structural stability has been...
The magnetization of FeSe1−xTex (x∼0, 0.5, and 1.0) compounds has been studied in magnetic fields up to 50kOe at temperatures 2–300K. superconducting transition was observed Tc∼8K 13.6–14.2K FeSe0.963 FeSe0.5Te0.5, respectively. For most the samples, nonlinearity curves normal state gives evidence a common, substantial presence ferromagnetic impurities these compounds. By taking impurity effects into account, intrinsic susceptibility χ FeSe0.963, FeTe estimated increase gradually with Te...
A detailed magnetization study for the novel FeSe superconductor is carried out to investigate behavior of intrinsic magnetic susceptibility χ in normal state with temperature and under hydrostatic pressure. The dependences its anisotropy Δχ = χ|| − χ⊥ are measured single crystals range 4.2–300 K, a substantial growth revealed. observed very large comparable averaged at low temperatures. For polycrystalline sample FeSe, significant pressure effect on determined be essentially dependent...
Magnetic properties of multi-walled carbon nanotubes modified with iron (MWCNT+Fe) are studied in detail the temperature range 4.2–300K. Carbon encapsulated Fe nanoparticles were produced by chemical vapor deposition. Low-temperature SQUID magnetization measurements supplemented structural studies employing thermogravimetric (TG) analysis, transmission electron microscopy (TEM), x-ray diffraction spectroscopy (XRD), and scanning (SEM). The magnetic susceptibility MWCNT+Fe was also above room...
The paper presents an analysis of the properties bulk superconducting magnesium diboride-based materials obtained by heating at high quasi-hydrostatic pressures (1–2 GPa), hot pressing (30 MPa), spark plasma sintering (16–96 MPa) and loose powder sintering. It is shown that optimization impurity distribution in MgB2 can be achieved varying synthesis conditions introducing dopants. In particular, polycrystalline synthesized 2 GPa containing a amount oxygen demonstrates critical current...
Abstract The magnetoresistance and electrical resistivity of nitrogen‐doped multi‐walled carbon nanotubes (N‐MWCNTs) were studied in the temperature range 1.6–100.3 1.6–286 K, respectively, using a standard four‐probe technique. possible mechanisms observed effects are discussed detail.
The seismic anisotropy of the Earth's core is believed to be due a preferred orientation hexagonal close packed (hcp) iron crystals that constitute dominating element in inner core. In this connection, magnetic properties hcp an external field are very interesting and studied here by employing ab initio full-potential linear muffin tin orbital method. By means susceptibility $\ensuremath{\chi}$ its energy for pressures temperatures corresponding conditions have been evaluated framework local...
A paramagnetic response of transition metals and itinerant d- f-metal compounds in an external magnetic field is studied by employing ab initio full-potential LMTO method the framework local spin density approximation. Within this anisotropy susceptibility hexagonal close-packed evaluated for first time. This owing to orbital Van Vleck-like susceptibility, which revealed be substantial transition-metal systems due hybridization effects electronic structure. It demonstrated that TiCo, Ni3Al,...
This paper describes the established correlations between characteristics of MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based superconducting materials and their structural features, in particular oxygen distribution content. As indicated by SEM Auger analysis, a sizeable amount is usually present (bulks, thin films, wires). The matrix phase bulk contains rather small amounts oxygen, but high dispersed inclusions or areas with...
The effect of pressure on the electronic structure and magnetic properties compounds YNi5, LaNi5, CeNi5 is studied. Large magnetovolume effects magnitude dlnχ∕dlnV≃4–7 are found for susceptibility χ these systems at low temperatures. Experimental data “first principles” calculations paramagnetic contributions to indicate that close a quantum critical point. It van Vleck orbital contribution 15–20% in exchange-enhanced materials should be taken into account analyzing experimental dlnχ∕dlnV....
The results of experimental investigations magnetoresistance in nanocarbon material (NCM) containing carbon nanotubes magnetic field up to 5 T and at temperature 0.54 K are reported. obtained curves NCM described satisfactorily within the framework shrinkage effect wave function localized state a along with spin-polarization mechanism.
The magnetic susceptibility χ of FeTex compounds () was studied under hydrostatic pressure up to 2 kbar at fixed temperatures 55, 78 and 300 K. Measurements were taken both for polycrystalline single crystalline samples. At ambient pressure, with decreasing temperature a drastic drop in χ(T) confirmed K, which appears be closely related antiferromagnetic ordering. obtained results have revealed puzzling growth this effect is enhanced by lowering the temperature. To shed light on effects...
The temperature dependences of the magnetic susceptibility χ and its anisotropy Δχ=χ∥−χ⊥ have been measured for hexagonal single crystals transition-metal diborides MB2 (M=Sc,Ti,V,Zr,Hf) in interval 4.2–300K. It is found that Δχ weakly temperature-dependent, a nonmonotonic function filling hybridized p−d conduction band, largest group-IV transition metals. First-principles calculations electronic structure values paramagnetic contributions (spin Van Vleck) to their show behavior due...
The effect of pressure on magnetic properties LaCoO3 is studied experimentally and theoretically. dependence susceptibility χ obtained by precise measurements as a function the hydrostatic P up to 2 kbar in temperature range from 78 K 300 K. A pronounced magnitude found be negative sign strongly dependent. experimental data are analysed using two-level model DFT+U calculations electronic structure LaCoO3. In particular, fixed spin moment method was employed obtain volume total energy...