A5066703017- Iron-based superconductors research
- Rare-earth and actinide compounds
- Advanced Condensed Matter Physics
- 2D Materials and Applications
- High-pressure geophysics and materials
- Topological Materials and Phenomena
- Chalcogenide Semiconductor Thin Films
- Magnetic and transport properties of perovskites and related materials
- Advanced Semiconductor Detectors and Materials
- Physics of Superconductivity and Magnetism
- Inorganic Chemistry and Materials
- Crystallization and Solubility Studies
- Superconductivity in MgB2 and Alloys
- Quantum Dots Synthesis And Properties
- X-ray Diffraction in Crystallography
- Crystal Structures and Properties
- Electronic and Structural Properties of Oxides
- Corporate Taxation and Avoidance
- Superconducting Materials and Applications
- Graphene research and applications
- Solid-state spectroscopy and crystallography
- Multiferroics and related materials
- Energetic Materials and Combustion
- Spectroscopy and Quantum Chemical Studies
- Metallurgical and Alloy Processes
Max Planck Institute for Chemical Physics of Solids
2015-2024
Max Planck Society
2008-2024
Samara National Research University
2023
Princeton University
2014
Max Planck Institute for Chemistry
2008-2012
Johannes Gutenberg University Mainz
2009-2011
Jilin University
2009
Russian Academy of Sciences
1998-2008
University of Saskatchewan
2008
University of Chicago
2008
Abstract Transition metal dichalcogenides have attracted research interest over the last few decades due to their interesting structural chemistry, unusual electronic properties, rich intercalation chemistry and wide spectrum of potential applications. Despite fact that majority related focuses on semiconducting transition-metal (for example, MoS 2 ), recently discovered unexpected properties WTe are provoking strong in semimetallic transition featuring large magnetoresistance,...
The metallization of hydrogen directly would require pressure in excess 400 gigapascals (GPa), out the reach present experimental techniques. dense group IVa hydrides attract considerable attention because these compounds is chemically precompressed and a metallic state expected to be achievable at experimentally accessible pressures. We report transformation insulating molecular silane metal 50 GPa, becoming superconducting transition temperature Tc = 17 kelvin 96 120 GPa. phase has...
${}^{57}$Fe-M\"ossbauer studies of superconducting Rb${}_{0.8}$Fe${}_{1.6}$Se${}_{2.0}$ with ${T}_{C}$ $=$ 32.4 K were performed on single-crystalline and polycrystalline samples in the temperature range 4.2--295 K. They reveal presence 88% magnetic 12% nonmagnetic Fe${}^{2+}$ species same polarization dependence their hyperfine spectra. The are attributed to 16$i$ sites $\sqrt{5}\ifmmode\times\else\texttimes\fi{}\sqrt{5}\ifmmode\times\else\texttimes\fi{}1$ superstructure Fe a nanosized...
The family of transition-metal dichalcogenides provides a rich platform for studying the interplay between crystal structure and electronic properties in strongly correlated electron systems. Applying external pressure as tuning parameter, authors observed striking correlation critical temperature ${T}_{c}$ superconductivity strength Se-Se bonds high-pressure pyrite phase PdSe${}_{2}$. bond length Se${}_{2}$ dimer was identified main parameter controlling structure. Strong pressure-induced...
The discovery of superconductivity in hafnium pentatelluride $\mathrm{HfT}{\mathrm{e}}_{5}$ under high pressure is reported. Two structural phase transitions and metallization with developing at around 5 GPa are observed. A maximal critical temperature 4.8 K attained a 20 GPa, persists up to the maximum study (42 GPa). combination electrical transport crystal structure measurements as well theoretical electronic calculations enables construction diagram pressure.
A pressure-induced topological quantum phase transition has been theoretically predicted for the semiconductor BiTeI with giant Rashba spin splitting. In this work, evolution of electrical transport properties in and BiTeBr is investigated under high pressure. The pressure-dependent resistivity a wide temperature range passes through minimum at around 3 GPa, indicating BiTeI. Superconductivity observed both while higher temperatures still exhibits semiconducting behavior. Theoretical...
We studied lithium azide (LiN3) by x-ray diffraction and Raman spectroscopy at hydrostatic compression up to pressures above 60 GPa room temperature. The results of analyses reveal the stability ambient-pressure C 2/m crystal structure highest pressure. pressure dependence librational modes provides evidence for an order–disorder transition low (below 3 GPa), similar observed previously temperatures. indicates that this is not associated with structural changes. phase LiN3 in contrast sodium...
Abstract Superconductivity and topological quantum states are two frontier fields of research in modern condensed matter physics. The realization superconductivity materials is highly desired; however, such typically limited to two-dimensional or three-dimensional far from being thoroughly investigated. In this work, we boost the electronic properties quasi-one-dimensional insulator bismuth iodide β-Bi 4 I by applying high pressure. observed for pressures, where temperature dependence...
The coexistence of charge density wave (CDW) and superconductivity in tantalum disulfide ($2\mathrm{H}\text{\ensuremath{-}}{\mathrm{TaS}}_{2}$) at low temperature is boosted by applying hydrostatic pressures to study both vibrational magnetic transport properties. Around ${P}_{c}$, we observe a superconducting dome with maximum transition ${T}_{c}=9.1\text{ }\text{ }\mathrm{K}$. First-principles calculations the electronic structure predict that, under ambient conditions, undistorted...
Unusual physical properties like large magnetoresistance (MR) and superconductivity occurring in semimetals with Dirac or Weyl points are often linked to their topologically nontrivial band structures. However, there is an increasing number of reports on that show MR the absence points. Herein we report experimental theoretical study layered transition-metal dichalcogenide (TMDC) $\mathrm{HfT}{\mathrm{e}}_{2}$ shows a $1350%$ at $T=2$ K...
The pressure effect on crystal structures, lattice vibrations, and electrical transport properties of $\mathrm{Pd}{\mathrm{S}}_{2}$ $\mathrm{NiS}{\mathrm{e}}_{2}$ were studied under high pressures up to \ensuremath{\sim}50 GPa using Raman spectroscopy resistivity measurements. undergoes semiconductor-to-metal transition at a \ensuremath{\sim}7 without structural phase transition. Structural the pyrite-type occurs \ensuremath{\sim}16 GPa. Superconductivity emerges in with well-defined...
CrI${}_{3}$, a member of the two-dimensional family materials, offers unique and very rich magnetic electronic phases. The authors show experimental evidence for transition from ferromagnetic semiconductor to antiferromagnetic metal at high pressure low temperature. junction between these phases is magnetically complex reminiscent quantum spin liquid or self-induced spin-glass state. Calculations using density functional theory suggest that competition intralayer interlayer interactions...
The temperature and pressure dependence of the partial density phonon states iron atoms in superconducting Fe1.01Se was studied by 57Fe nuclear inelastic scattering (NIS). high energy resolution allows for a detailed observation spectral properties. A sharpening optical modes shift all features towards higher energies ~4% with decreasing from 296 K to 10 found. However, no detectable change at tetragonal - orthorhombic phase transition around 100 observed. Application 6.7 GPa, connected an...
Iron(IV) oxides are strongly correlated materials with negative charge-transfer energy (negative \ensuremath{\Delta}), and exhibit peculiar electronic magnetic properties such as topological helical spin structures in the metallic cubic perovskite ${\mathrm{SrFeO}}_{3}$. Here, structure of layered negative-\ensuremath{\Delta} insulator ${\mathrm{Sr}}_{2}{\mathrm{FeO}}_{4}$ was studied by powder neutron diffraction zero field fields up to 6.5 T. Below...
High-pressure magnetization, structural and 57Fe M\"ossbauer studies were performed on superconducting Rb0.8Fe1.6Se2.0 with Tc = 32.4 K. The transition temperature gradually decreases increasing pressure up to 5.0 GPa followed by a marked step-like suppression of superconductivity near 6 GPa. No phase in the Fe vacancy-ordered superstructure is observed synchrotron XRD 15.6 GPa, while spectra above 5 reveal appearance new paramagnetic significant changes magnetic electronic properties...
Functional oxides whose physicochemical properties may be reversibly changed at standard conditions are potential candidates for the use in next-generation nanoelectronic devices. To date, vanadium dioxide (VO2 ) is only known simple transition-metal oxide that demonstrates a near-room-temperature metal-insulator transition used such appliances. In this work, we synthesized and investigated crystals of novel mixed-valent iron with an unconventional Fe5 O6 stoichiometry. Near 275 K, undergoes...
The structural and electronic properties of $\mathrm{BaC}{\mathrm{r}}_{2}\mathrm{A}{\mathrm{s}}_{2}$, which is isostructural to the 122 iron arsenide superconductors, are studied at high pressures using synchrotron x-ray powder diffraction, electrical resistivity measurements, first-principles calculations. At a pressure about 18.5 GPa, an phase transition collapsed tetragonal observed, similar that in $\mathrm{BaF}{\mathrm{e}}_{2}\mathrm{A}{\mathrm{s}}_{2}$. In both phases,...
A Weyl semimetal with strong electron-phonon interaction can show axionic coupling in its insulator state at low temperatures, owing to the formation of a charge density wave (CDW). Such CDW emerges linear-chain-compound ${\mathrm{Ta}}_{2}{\mathrm{Se}}_{8}\mathrm{I}$ below 263 K, resulting appearance dynamical condensed-matter axion quasiparticle. In this paper, we demonstrate that interchain be varied suppress pressure, while retaining phase high temperatures. Above 17 GPa, does not...