A5049077314- Magnetic and transport properties of perovskites and related materials
- Iron-based superconductors research
- Rare-earth and actinide compounds
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Layered Double Hydroxides Synthesis and Applications
- Corporate Taxation and Avoidance
- Ferroelectric and Piezoelectric Materials
- Superconductivity in MgB2 and Alloys
- Magnetic Properties of Alloys
- Graphene research and applications
- Boron and Carbon Nanomaterials Research
- Carbon Nanotubes in Composites
- Physics of Superconductivity and Magnetism
- Diamond and Carbon-based Materials Research
- Surface and Thin Film Phenomena
- Thermal Expansion and Ionic Conductivity
- High-pressure geophysics and materials
- Magnetic properties of thin films
- Catalytic Processes in Materials Science
- X-ray Diffraction in Crystallography
- Magnetism in coordination complexes
- Advanced Photocatalysis Techniques
- Crystallization and Solubility Studies
- Organic and Molecular Conductors Research
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine
2013-2023
National Academy of Sciences of Ukraine
2012-2023
Institute of Physics of the Slovak Academy of Sciences
2015-2018
University of Pavol Jozef Šafárik
2015-2018
V.E. Lashkaryov Institute of Semiconductor Physics
2012
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...
Abstract Neutron powder diffraction measurements on the 35 % La-substituted Bi 1− x La Fe 0.5 Sc O 3 composition revealed that samples obtained under high-pressure (6 GPa) and high-temperature (1500 K) conditions crystalize into a distorted perovskite structure with orthorhombic Pnma symmetry unit cell parameters: o = 5.6745(2) Å, b 7.9834(3) Å c 5.6310(2) Å. A long-range magnetic ordering takes place below 220 K implies G -type moments 4.10(4) μ B per aligned predominately along -axis. The...
A post-synthesis thermal treatment of metastable phases in the high-pressure stabilised perovskite BiFe1-yScyO3 system results irreversible formation polymorphs which represent novel polar and antipolar structures with interesting magnetic properties. Such annealing-stimulated polymorphism is believed to be a general phenomenon can found other systems.
A 20% substitution of Bi with La in the perovskite ${\mathrm{Bi}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}{\mathrm{Fe}}_{0.5}{\mathrm{Sc}}_{0.5}{\mathrm{O}}_{3}$ system obtained under high-pressure and high-temperature conditions has been found to induce an incommensurately modulated structural phase. The room-temperature x-ray neutron powder diffraction patterns this phase were successfully refined using $Imma(0,0,\ensuremath{\gamma})s00$ superspace group ($\ensuremath{\gamma}=0.534(3)$)...
Magnetic behavior of CoII(n)AlIII layered double hydroxides (LDHs) (n = Co/Al 2 and 3) intercalated with nitrate was studied as a function temperature. Both LDH compounds are paramagnetic above about 8 K. A rapid increase their magnetic moments occurs below this temperature until the reach maximum values at Tmax 4.0 K 3.2 for Co(2)Al–NO3 Co(3)Al–NO3, respectively. Below Tmax, zero-field-cooled field-cooled static magnetization curves strongly different. Along low-temperature phenomena,...
The low-temperature heat capacity and the magnetisation of Co2+nAl3+ layered double hydroxides (LDH) with cobalt-to-aluminium ratio n = 2 3 intercalated different anions have been studied in a wide range magnetic fields up to 50 kOe. capacity, C(T), was found demonstrate Schottky-like anomaly observed as broad local maximum temperature dependence below 10 K. effect is caused by splitting ground-state Kramers doublet Co2+ internal exchange field correlates ordering these LDH. In low applied...
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...
Below the Néel temperature, TN ∼ 220 K, at least two nano-scale antiferromagnetic (AFM) phases coexist in polar polymorph of BiFe0.5Sc0.5O3 perovskite; one these is a weak ferromagnetic. Non-uniform structure distortions induced by high-pressure synthesis lead to competing AFM orders and spontaneous magnetic phase separated state compound. Interface exchange coupling between domains ferromagnetic causes unidirectional anisotropy magnetization, resulting bias (EB) effect. The EB field, HEB,...
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...
High-quality stoichiometric Co2Al–NO3 and Co2Al–CO3 layered double hydroxides (LDHs) have been obtained by precipitation followed anion exchange, both high-power-sonication assisted. Application of high-power ultrasound has demonstrated to result in a considerable acceleration the crystallization process anion-exchange reaction. Two independent approaches were used form bulk 2-D samples with oriented crystallites, namely uniaxial pressing deposits from sonicated LDH slurries magnetic...
The temperature behavior of the crystal structure as well dielectric and magnetic properties perovskite bismuth chromate ceramics with 10 mol % Cr3+-to-Sc3+ substitution were studied compared those unmodified compound. Using a high-pressure synthesis, BiCrO3 BiCr0.9Sc0.1O3 obtained metastable phases which are monoclinic C2/c √6ap × √2ap superstructure (where ap is primitive unit-cell parameter) under ambient conditions. At room temperature, unit cell volume ∼1.3% larger than that BiCrO3....
Magnetic properties of the high-pressure stabilized perovskite BiFe1-yScyO3 phases (0.1 ≤ y 0.9) have been studied by means magnetization measurements and neutron diffraction. The metastable perovskites this series undergo irreversible polymorphic transformations upon annealing, phenomenon referred to as conversion polymorphism. It has found that solid solutions with ≥ 0.70 exhibit no long-range magnetic ordering regardless their polymorph modification, while those 0.60 are all...
The temperature dependence and the effect of pressure P up to 2 kbar on magnetic susceptibility χ tetraborides SmB4 YbB4 was studied. For compound CeB4, electronic structure were calculated from first principles as a function atomic volume. results show that in studied tetraborides, rare-earth ions (Ce4+, Sm3+ Yb2.8+) exhibit different valence states, which determines specific features their properties. In particular, obtained derivatives dlnχ/dP for cerium, samarium ytterbium are −2, −0.6...
The effect of isotropic pressures P up to 5 kbar on the superconducting transition temperature Tc FeSe1−xTex system (x = 0, 0.85, 0.88, 0.90) is studied. For first time, a change in sign pressure going from FeSe tellurium-rich alloys observed. This makes it possible specify more precisely form dependence derivative dTc/dP composition this system. compared with principles calculations electron structure and magnetism FeSe, FeTe, FeSe0.5Te0.5 as functions pressure, well our earlier...