Related papers: Volume Collapse Without a Structural Transition in…
The pressure-dependent relation between Eu valence and lattice structure in model compound EuO is studied with synchrotron-based x-ray spectroscopic and diffraction techniques. Contrary to expectation, a 7% volume collapse at $\approx$ 45…
The local electronic and magnetic properties of superconducting FeSe have been investigated by K$\beta$ x-ray emission (XES) and simultaneous x-ray absorption spectroscopy (XAS) at the Fe K-edge at high pressure and low temperature. Our…
The high-pressure behavior of monoclinic VO$_2$ is revisited by a combination of Raman spectroscopy and X-ray diffraction on a single crystal under hydrostatic conditions at room temperature. A soft mode is observed up to P$_c$ = 13.9(1)…
We present a detailed theoretical study of the electronic, magnetic, and structural properties of magnesiow\"ustite Fe$_{1-x}$Mg$_x$O with $x$ in the range between 0$-$0.875 using a fully charge self-consistent implementation of the density…
Motivated by pressure experiments on FeAs-122 superconductors, we propose a scenario based on local-moment physics to explain the simultaneous disappearance of magnetism, reduction of the unit cell volume, and decrease in resistivity. In…
We have studied the volume collapse of LaMnO$_3$ at the Jahn- Teller (JT) transition temperature T$_{JT}$=750 K which has recently been found in high temperature powder x- ray and neutron diffraction experiments. We construct a model…
Oxygen and other light elements comprise up to 5 wt% of the Earth's outer-core, and may significantly influence its physical properties and the operation of the geodynamo. Here we report in situ x-ray diffraction measurements of Fe, Fe +…
We report on the synthesis of superconducting single crystals of FeSe, and their characterization by X-ray diffraction, magnetization and resistivity. We have performed ac susceptibility measurements under high pressure in a hydrostatic…
The structural, vibrational, electronic, and magnetic properties of inverse spinel $Co_2TiO_4$ (CTO-Sp) under high-pressure (HP) conditions are systematically investigated using X-ray diffraction, Raman spectroscopy, in situ optical…
We report a detailed investigation of GdO$_{1-x}$F$_{x}$FeAs (x = 0, 0.07 and 0.14) samples by means of high-field/high-frequency electron spin resonance (HF-ESR) together with measurements of thermodynamic and transport properties. The…
(MgFe)O is a solid solution with ferrous iron undergoing the high to low spin state (HS-LS) crossover under high pressure. The exact state of the material in the region of the crossover is still a mystery, as domains with different spin…
The accuracy of LDA + U total energies is tested by predicting the high pressure behavior of rocksalt-structured FeO, including metal-insulator and magnetic transitions, equation of state, and lattice strain, as functions of the Coulomb…
The recent surge of interest in phase change materials GeTe, Ge$_2$Sb$_2$Te$_5$, and related compounds motivated us to revisit the structural phase transition in GeTe in more details than was done before. Rhombohedral-to-cubic ferroelectric…
It is argued that the formation of the non-magnetic state of FeS in external pressures above 6.5 GPa is in agreement with the prediction of the quantum atomistic solid-state theory, an extension of the crystal-field theory with the…
The structural properties of LaCoO3 were studied by means of high-resolution neutron powder diffraction in the temperature range 5<T<1000 K. Changes of the Co+3 spin states in this temperature interval are shown to affect not only the unit…
We investigate the crystal structure and lattice vibrations of Sr$_2$IrO$_4$ by a combined phonon Raman scattering and x-ray powder diffraction experiment under pressures up to $66$ GPa and room temperature. Density functional theory (DFT)…
In-situ high pressure single crystal X-ray diffraction study reveals that the quantum material CaMn$_2$Bi$_2$ undergoes a unique plane to chain structural transition between 2 and 3 GPa, accompanied by a large volume collapse. CaMn2Bi2…
The results of magnetic and spectral properties calculation for paramagnetic phase of ferropericlase (Fe$_{1/4}$Mg$_{3/4}$)O at ambient and high pressures are reported. Calculations were performed by combined Local Density Approximation +…
In a joint experimental and theoretical study, we investigate the isostructural collapse from the ambient pressure tetragonal phase to a collapsed tetragonal phase for non-superconducting metallic SrFe2As2 and SrFe_1.8Ru_0.2As_2. The…
We report the evolution of the electronic nematic susceptibility in FeSe via Raman scattering as a function of hydrostatic pressure up to 5.8 GPa where the superconducting transition temperature $T_{c}$ reaches its maximum. The critical…