A5072970780- Advanced Condensed Matter Physics
- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Iron-based superconductors research
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Crystal Structures and Properties
- Crystallization and Solubility Studies
- Rare-earth and actinide compounds
- X-ray Diffraction in Crystallography
- Multiferroics and related materials
- Magnetism in coordination complexes
- Corporate Taxation and Avoidance
- Polyoxometalates: Synthesis and Applications
- Theoretical and Computational Physics
- High-pressure geophysics and materials
- Ferroelectric and Piezoelectric Materials
- Organic and Molecular Conductors Research
- Chemical Synthesis and Characterization
- Lanthanide and Transition Metal Complexes
- Inorganic Chemistry and Materials
- Magnetic Properties of Alloys
- Nuclear physics research studies
- Superconductivity in MgB2 and Alloys
Lomonosov Moscow State University
2016-2025
National University of Science and Technology
2016-2025
National University of Science and Technology
2015-2024
Moscow State University
2010-2024
Ural Federal University
2014-2023
Institute for High Energy Physics
2013-2023
Kurchatov Institute
2012-2023
Argonne National Laboratory
2008-2023
Ball State University
2000-2023
Frankfurt Institute for Advanced Studies
2023
The particular shape of the Fermi surface can give rise to a number collective quantum phenomena in solids, such as density wave orderings or even superconductivity. In many new iron superconductors this shape, 'nested' surface, is indeed observed, but its role formation spin-density waves superconductivity not clear. We have studied electronic structure non-magnetic LiFeAs (Tc~18K) superconductor using angle-resolved photoemission spectroscopy. find notable absence nesting, strong...
Abstract Elucidating the nature of magnetism a high-temperature superconductor is crucial for establishing its pairing mechanism. The parent compounds cuprate and iron-pnictide superconductors exhibit Néel stripe magnetic order, respectively. However, FeSe, structurally simplest iron-based superconductor, shows nematic order ( T s =90 K), but not in phase, ground state intensely debated. Here we report inelastic neutron-scattering experiments that reveal both spin fluctuations over wide...
Abstract There is a long time gap between the formulation of basic theory low-dimensional (low-D) magnetism as advanced by Ising, Heisenberg and Bethe its experimental verification. The latter started not before discovery high- T C superconductivity in cuprates has been boosted this result an impressive succession newly observed physical phenomena. Milestones on road were compounds which reached their quantum ground states upon lowering temperature either gradually or through different...
Neutron diffraction and bulk measurements are used to determine the nature of low-temperature ordered state in ${\mathrm{LiCu}}_{2}{\mathrm{O}}_{2}$, a $S=1/2$ spin-chain compound with competing interactions. The spin structure is found be helimagnetic, propagation vector $(0.5,\ensuremath{\zeta},0)$, $\ensuremath{\zeta}=0.174$. nearest-neighbor exchange constant frustration ratio estimated ${J}_{1}=5.8\text{ }\mathrm{meV}$ ${J}_{2}/{J}_{1}=0.29$, respectively. For idealized quantum chains,...
Ferromagnetic shape memory alloys Ni$_{2+x}$Mn$_{1-x}$Ga were studied in the range of compositions $0.16 \le x 0.36$. Experimental phase diagram, constructed from differential scanning calorimetry, transport and magnetic measurements, exhibits distinctive feature a compositional interval $0.18 0.27$, where martensitic transitions merge first-order magnetostructural transition ferromagnetic martensite $\leftrightarrow$ paramagnetic austenite. Observed this non-monotonous behavior temperature...
The electronic structure of the iron chalcogenide superconductor FeSe_{1-x} was investigated by high- resolution angle-resolved photoemission spectroscopy (ARPES). results were compared to DFT calculations showing some significant differences between experimental FeSe_{1-x}, and existing data on FeSe_{x}Te_{1-x}. bands undergo a pronounced orbital dependent renormalization, different from what observed for FeSe_{x}Te_{1-x} any other pnictides.
From thermodynamics, local spin density approximation+Hubbard U studies and exact diagonalizations of a five-band Hubbard model on CuO2 stripes we find that Li2ZrCuO4 (Li2CuZrO4 in traditional notation) is close to ferromagnetic critical point. Analyzing its susceptibility chi(T) specific heat cp(T,H) within Heisenberg model, show the ratio 2nd 1st neighbor exchange integrals alpha=-J2/J1 approximately 0.3 value alphac=1/4. Comparing with related chain cuprates explain rather strong field...
FeSe layer-based superconductors exhibit exotic and distinctive properties. The undoped shows nematicity superconductivity, while the heavily electron-doped KxFe2-ySe2 single-layer FeSe/SrTiO3 possess high superconducting transition temperatures that pose theoretical challenges. However, a comprehensive study on doping dependence of an superconductor is still lacking due to lack clean means control. Through angle-resolved photoemission spectroscopy studies K-dosed thick films FeSe0.93S0.07...
Long-lasting anticorrosive coatings for steel have been developed on the basis of halloysite nanotubes loaded with three corrosion inhibitors: benzotriazole, mercaptobenzothiazole, and mercaptobenzimidazole. The inhibitors' tubes were admixed at 5-10 wt % to oil-based alkyd paint providing sustained agent release healing in coating defects. slow 20-30 h inhibitors defect points caused a remarkable improvement anticorrosion efficiency coatings. Further time expansion has achieved by formation...
The plate-like single crystals of tetragonal (P4/nmm) FeSe1−x superconductors were grown using the KCl–AlCl3 flux technique which produced crystalline samples about 4 × 0.1 mm3 dimensions. energy dispersive X-ray spectroscopy established a ratio Fe : Se = 1 0.96 ± 0.02. resistivity and magnetization measurements revealed sharp superconducting transition at Tc 9.4 K. Multiple Andreev reflections pointed to existence two-gap superconductivity with gap values ΔL 2.4 0.2 meV ΔS 0.75 4.2
We investigate the temperature dependence of lower critical field ${H}_{c1}(T)$ a high-quality FeSe single crystal under static magnetic fields $H$ parallel to $c$ axis. The first vortex penetration has been experimentally obtained by two independent methods and corresponding was deduced taking into account demagnetization factors. A pronounced change in ${H}_{c1}$(T) curvature is observed, which attributed anisotopic s-wave or multiband superconductivity. London depth...
The recent discovery of high-temperature superconductivity in single-layer iron selenide has generated significant experimental interest for optimizing the superconducting properties iron-based superconductors through lattice modification. For simulating similar effect by changing chemical composition due to S doping, we investigate high-quality single crystals ${\mathrm{FeSe}}_{1\ensuremath{-}x}{\mathrm{S}}_{x}$ ($x=0$, 0.04, 0.09, and 0.11) using magnetization, resistivity, London...
The quasi-one-dimensional helimagnet $\mathrm{Li}{\mathrm{Cu}}_{2}{\mathrm{O}}_{2}$ was studied by single crystal inelastic neutron scattering. dispersion relation of spin wave excitations measured in the vicinity principal magnetic Bragg reflection. A theoretical analysis data yields an estimate relevant exchange constants and explains mechanism geometric frustration that leads to helimagnetism. It is found simple antiferromagnetic ${J}_{1}\text{\ensuremath{-}}{J}_{2}$ model previously...
The comprehensive low-temperature specific heat C(T) data identify both an isotropic s-wave and extended order parameters coexisting in a superconducting single crystal FeSe with Tc=8.11 K. gap {\Delta}0=1.33 meV on the hole Fermi sheets {\Delta}={\Delta}e(1+\alpha*cos2_theta) {\Delta}e=1.13 \alpha=0.78 electron sheets. is rather anisotropic but low energy quasiparticle excitations demonstrate no sign of accidental nodes. coefficient \gamma(H) manifesting contribution to C non-linear...
Abstract Crystalline silicon (Si) nanoparticles present an extremely promising object for bioimaging based on photoluminescence (PL) in the visible and near-infrared spectral regions, but their efficient PL emission aqueous suspension is typically observed after wet chemistry procedures leading to residual toxicity issues. Here, we introduce ultrapure laser-synthesized Si-based quantum dots (QDs), which are water-dispersible exhibit bright exciton window of relative tissue transparency near...
FeSe exhibits a novel ground state in which superconductivity coexists with nematic order the absence of any long-range magnetic order. Here, we report on an angle-resolved photoemission study superconducting gap structure FeSe_{0.93}S_{0.07}, without complications caused by Fermi surface reconstruction induced We find that shows pronounced twofold anisotropy around elliptical hole pocket near Z (0, 0, π), minima at end points its major axis, while no detectable is observed Γ 0) and zone...
We present a comprehensive experimental and theoretical study of the electronic magnetic properties two quasi-two-dimensional (2D) honeycomb lattice monoclinic compounds ${A}_{3}\mathrm{N}{\mathrm{i}}_{2}\mathrm{Sb}{\mathrm{O}}_{6}\phantom{\rule{0.16em}{0ex}}(A=\mathrm{Li},\phantom{\rule{0.16em}{0ex}}\mathrm{Na})$. Magnetic susceptibility specific heat data are consistent with onset antiferromagnetic long-range order N\'eel temperatures \ensuremath{\sim}14 16 K for...
Recent theoretical studies have suggested that Kitaev physics and such effects as formation of a mysterious spin-liquid state can be expected not only in $\ensuremath{\alpha}\text{\ensuremath{-}}{\mathrm{RuCl}}_{3}$ iridates, but also conventional $3d$ transition metal compounds. Using dc ac magnetometry, thermodynamic, $^{23}\mathrm{Na}$ nuclear magnetic resonance (NMR) measurements we studied candidate material ${\mathrm{Na}}_{3}{\mathrm{Co}}_{2}{\mathrm{SbO}}_{6}$. A full phase diagram...