Publications (29)
Mott-Hubbard gap closure and structural phase transition in the oxyhalides TiOBr and TiOCl under pressure
C. A. Kuntscher, A. Pashkin, H. Hoffmann +9
Pressure-dependent transmittance and reflectance spectra of TiOBr and TiOCl single crystals at room temperature suggest the closure of the Mott-Hubbard gap, i.e., the gap is filled…
Revealing the complex nature of bonding in binary high-pressure compound FeO
E. Koemets, I. Leonov, M. Bykov +21
Extreme pressures and temperatures are known to drastically affect the chemistry of iron oxides resulting in numerous compounds forming homologous series FeOFeO…
High-pressure versus isoelectronic doping effect on the honeycomb iridate NaIrO
V. Hermann, J. Ebad-Allah, F. Freund +7
We study the effect of isoelectronic doping and external pressure in tuning the ground state of the honeycomb iridate NaIrO by combining optical spectroscopy with synchrotr…
Pressure-induced ferromagnetism due to an anisotropic electronic topological transition in Fe1.08Te
K. Mydeen, D. Kasinathan, C. Koz +8
A rapid and anisotropic modification of the Fermi-surface shape can be associated with abrupt changes in crystalline lattice geometry or in the magnetic state of a material. In thi…
Pressure-driven orbital reorientation and change in Mott-Hubbard gap in YTiO3
I. Loa, X. Wang, K. Syassen +4
We investigate the crystal structure of YTiO3 at high pressures up to 30 GPa by synchrotron x-ray powder diffraction (T = 295 K). The variation of the Ti--O bond lengths with press…
Plasmons in Sodium under Pressure: Increasing Departure from Nearly-Free-Electron Behavior
I. Loa, K. Syassen, G. Monaco +3
We have measured plasmon energies in Na under high pressure up to 43 GPa using inelastic x-ray scattering (IXS). The momentum-resolved results show clear deviations, growing with i…
Effect of pressure on the magnetostructural transition in SrFe2As2
M. Kumar, M. Nicklas, A. Jesche +7
We present a systematic pressure study of poly- and single crystalline SrFe2As2 by electrical resistivity and X-ray diffraction measurements. SrFe2As2 exhibits a structural phase t…
Importance of correlation effects in hcp iron revealed by a pressure-induced electronic topological transition
K. Glazyrin, L. V. Pourovskii, L. Dubrovinsky +17
We discover that hcp phases of Fe and Fe0.9Ni0.1 undergo an electronic topological transition at pressures of about 40 GPa. This topological change of the Fermi surface manifests i…
Tuning the Eu valence in EuPd_3B_x: pressure versus valence electron count - a combined computational and experimental study
M. Schmitt, R. Gumeniuk, A. Trapananti +8
In a joint theoretical and experimental study we investigate the pressure dependence of the Eu valence in EuPd_3B_x (0 <= x <= 1). Density functional band structure calculations ar…
Two pressure-induced structural phase transitions in TiOCl
J. Ebad-Allah, A. Schönleber, S. van Smaalen +7
We studied the crystal structure of TiOCl up to pressures of =25~GPa at room temperature by x-ray powder diffraction measurements. Two pressure-induced structural phase transiti…
Structural properties of the sesquicarbide superconductor La2C3 at high pressure
X. Wang, I. Loa, K. Syassen +4
The effect of pressure on the structural properties of lanthanum sesquicarbide La2C3 (T_c = 13 K) has been investigated at room temperature by angle-dispersive powder x-ray diffrac…
Pressure dependence of the structure and electronic properties of Sr3Ir2O7
C. Donnerer, Z. Feng, J. G. Vale +9
We study the structural evolution of SrIrO as a function of pressure using x-ray diffraction. At a pressure of 54 GPa at room temperature, we observe a first-order stru…
Pressure-induced metallization and structural phase transition of the Mott-Hubbard insulator TiOBr
C. A. Kuntscher, S. Frank, A. Pashkin +9
We investigated the pressure-dependent optical response of the low-dimensional Mott-Hubbard insulator TiOBr by transmittance and reflectance measurements in the infrared and visibl…
Suppression of the ferromagnetic order in the Heusler alloy Ni50Mn35In15 by hydrostatic pressure
C. Salazar Mejia, K. Mydeen, P. Naumov +7
We report the effect of hydrostatic pressure on the magnetic and structural properties of the shape-memory Heusler alloy Ni50Mn35In15. Magnetization and x-ray diffraction experimen…
Pressure-induced formation of rhodium zigzag chains in the honeycomb rhodate LiRhO
V. Hermann, S. Biswas, J. Ebad-Allah +8
We use powder x-ray diffraction to study the effect of pressure on the crystal structure of the honeycomb rhodate LiRhO. We observe low-pressure ( = 6.5 GPa)…
Pressure dependence of the charge density wave in 1T-TaS2 and its relation to superconductivity
T. Ritschel, J. Trinckauf, G. Garbarino +5
We present a state-of-the-art x-ray diffraction study of the charge density wave order in 1T-TaS2 as a function of temperature and pressure. Our results prove that the charge densi…
Structural investigations on -FeGe at high pressure and low temperature
H. Wilhelm, M. Schmidt, R. Cardoso-Gil +4
The structural parameters of -FeGe have been determined at ambient conditions using single crystal refinement. Powder diffraction have been carried out to determine structural…
Pressure-induced order-disorder phase transition in superconducting CaC6
A. Gauzzi, N. Bendiab, M. d'Astuto +9
By means of synchrotron X-ray diffraction, we studied the effect of high pressure, P, up to 13 GPa on the room temperature crystal structure of superconducting CaC6. In this P rang…
Metallic State in Cubic FeGe beyond its Quantum Phase Transition
P. Pedrazzini, H. Wilhelm, D. Jaccard +8
We report on results of electrical resistivity and structural investigations on the cubic modification of FeGe under high pressure. The long-wavelength helical order ( K)…
Deconfinement transition and dimensional crossover in the Bechgaard-Fabre salts: pressure- and temperature-dependent optical investigations
A. Pashkin, M. Dressel, M. Hanfland +1
The infrared response of the organic conductor (TMTSF)PF and the Mott insulator (TMTTF)PF are investigated as a function of temperature and pressure and for the pol…
High pressure effect on superconductivity of YB6
S. Gabáni, I. TakáÄová, G. Pristáš +8
Pressure effect on superconducting properties of two YB6 samples (Tc = 5.9 and 7.5 K) were investigated by measurements of electrical resistivity, magnetic susceptibility, and X-ra…
FeOOH instability at the lower mantle conditions
E. Koemets, T. Fedotenko, S. Khandarkhaeva +12
Goethite, α-FeOOH, is a major component among oxidized iron species, called rust, which formed as a product of metabolism of anoxygenic prokaryotes (1, 2) inhabiting the Earth fro…
Gibbs energy of ices III, V and VI: wholistic thermodynamics and elasticity of the water phase diagram to 2300 MPa
B. Journaux, J. M. Brown, A. Pakhomova +7
Gibbs energy representations for ice III, V and VI are reported. These were constructed using new measurements of volumes at high pressure over a range of low temperatures combined…
Quantum and Classical Orientational Ordering in Solid Hydrogen
I. I. Mazin, R. J. Hemley, A. F. Goncharov +2
We present a unified view of orientational ordering in phases I, II, and III of solid hydrogen. Phases II and III are orientationally ordered, while the ordering objects in phase I…
Pressure-induced phase transitions and high-pressure tetragonal phase of Fe1.08Te
C. Koz, S. RöÃler, A. A. Tsirlin +6
We report the effects of hydrostatic pressure on the temperature-induced phase transitions in Fe1.08Te in the pressure range 0-3 GPa using synchrotron powder x-ray diffraction (XRD…
Competition between spin-orbit coupling, magnetism, and dimerization in the honeycomb iridates: -LiIrO under pressure
V. Hermann, M. Altmeyer, J. Ebad-Allah +9
Single-crystal x-ray diffraction studies with synchrotron radiation on the honeycomb iridate -LiIrO reveal a pressure-induced structural phase transition with symme…
Pressure-induced quenching of the charge-density-wave state observed by x-ray diffraction
A. Sacchetti, C. L. Condron, S. N. Gvasaliya +11
We report an x-ray diffraction study on the charge-density-wave (CDW) LaTe and CeTe compounds as a function of pressure. We extract the lattice constants and the CDW modula…
Pressure-induced structural phase transition in the Bechgaard-Fabre salts
A. Pashkin, M. Dressel, S. G. Ebbinghaus +2
The crystal structures of the quasi-one-dimensional organic salts (TMTTF)PF and (TMTSF)PF were studied by pressure-dependent x-ray diffraction up to 10 GPa at room…
Crystal structure of LaTiO_3.41 under pressure
I. Loa, K. Syassen, X. Wang +3
The crystal structure of the layered, perovskite-related LaTiO_3.41 (La_5Ti_5O_{17+δ}) has been studied by synchrotron powder x-ray diffraction under hydrostatic pressure up to 27…