Related papers: Combined first-principles and EXAFS study of struc…
We investigate the low energy acoustical and optical modes in $\mathrm{HgBa_2CuO_{4+\delta}}$ using inelastic x-ray scattering (IXS). The experimental phonon dispersion and the dynamical structure factor are compared with an atomic shell…
We discuss the first infrared reflectivity measurement on a BiFeO3 single crystal between 5 K and room temperature. The 9 predicted ab-plane E phonon modes are fully and unambiguously determined. The frequencies of the 4 A1 c-axis phonons…
In contrast to the previous reports that the divalent perovskite SrCrO$_3$ was believed to be cubic structure and nonmagnetic metal, recent measurements suggest coexistence of majority tetragonally distorted weak antiferromagnetic phase and…
Organic-inorganic halide perovskites (OIHPs) are promising optoelectronic materials, but their instability under radiation environments restricts their durability and practical applications. Here we employ electron and synchrotron X-ray…
We investigated the crystal structure and lattice excitations of the ternary intermetallic stannide Ca3Ir4Sn13 using neutron and x-ray scattering techniques. For T > T* ~ 38 K the x-ray diffraction data can be satisfactorily refined using…
The formation of precipitated zirconium (Zr) hydrides is closely related to the hydrogen embrittlement problem for the cladding materials of pressured water reactors (PWR). In this work, we systematically investigated the crystal structures…
The local crystal structures of many perovskite-structured materials deviate from the average space group symmetry. We demonstrate, from lattice-dynamics calculations based on quantum chemical force constants, that all the caesium-lead and…
The local environment and the charge state of a nickel impurity in cubic Ba$_{0.8}$Sr$_{0.2}$TiO$_3$ are studied by XAFS spectroscopy. According to the XANES data, the mean Ni charge state is $\sim$2.5+. An analysis of the EXAFS spectra and…
In this present study, the pseudopotential plane-wave (PP-PW) pathway in the scheme of density functional theory (DFT) is utilized to investigate the various physical properties on (Ba0.82K0.18)(Bi0.53Pb0.47)O3 (BKBPO) single perovskite…
Pulsed neutron spectroscopy is used to make absolute measurements of the dynamic magnetic susceptibility of insulating YBa2Cu3O6.15. Acoustic and optical modes, derived from in- and out-of-phase oscillation of spins in adjacent CuO2 planes,…
We report on the high-temperature evolution of far- and mid- infrared reflectivity and emissivity spectra of ambient orthorhombic ErMnO3 from 12 K to sample decomposition above 1800 K. At low temperatures the number of phonons agrees with…
The electronic and local structural properties of CuO under pressure have been investigated by means of X-ray absorption spectroscopy (XAS) at Cu K edge and ab-initio calculations, up to 17 GPa. The crystal structure of CuO consists of Cu…
Spin-orbit coupling in heavy 5$d$ metal oxides, in particular, iridates have received tremendous interest in recent years due to the realization of exotic electronic and magnetic phases. Here, we report the synthesis, structural, magnetic,…
Extensive inelastic neutron scattering measurements of phonons on a single crystal of CaFe2As2 allowed us to establish a fairly complete picture of phonon dispersions in the main symmetry directions. The phonon spectra were also calculated…
We present a first-principles investigation of structural and elastic properties of experimentally observed phases of bulk SrRuO$_3$ - namely orthorhombic, tetragonal, and cubic - by applying density functional theory (DFT) approximations.…
The vibrational spectra and short-range structure of the brownmillerite-type oxide Ba$_{2}$In$_{2}$O$_{5}$ and its hydrated form BaInO$_{3}$H, are investigated by means of Raman, infrared, and inelastic neutron scattering spectroscopies…
Sodium niobate (NaNbO3) exhibits most complex sequence of structural phase transitions in perovskite family and therefore provides as excellent model system for understanding the mechanism of structural phase transitions. We report…
On the basis of density functional theory electronic band structure calculations using the augmented spherical wave method, the electronic and magnetic properties of the orthorhombic and tetragonal phases of Ca3Mn2O7 were investigated and…
We use ab initio simulations to investigate the properties of a sodium borosilicate glass of composition 3Na_2O-B_2O_3-6SiO_2. We find that the broadening of the first peak in the radial distribution functions g_BO(r) and g_BNa(r) is due to…
We study the structural evolution of Sr$_3$Ir$_2$O$_7$ as a function of pressure using x-ray diffraction. At a pressure of 54 GPa at room temperature, we observe a first-order structural phase transition, associated with a change from…