相关论文: Structural phase transitions in perovskite BaCeO3 …

Here we report a structural phase transition and its possible competition with superconductivity in the suboxide La$_5$Pb$_3$O. Upon cooling through $T_t$ = 225 K, La$_5$Pb$_3$O transforms from a high-temperature I4/mcm to a low-temperature…

The structural phase transition in hexagonal BaMnO$_3$ occurring at $T_c$=130 K was studied in ceramic samples using electron and X-ray diffraction, second harmonic generation as well as by dielectric and lattice dynamic spectroscopies. The…

Lead titanate (PbTiO3) is a classical example of a ferroelectric perovskite oxide illustrating a displacive phase transition accompanied by a softening of a symmetry-breaking mode. The underlying assumption justifying the soft-mode theory…

PbTiO3 has the highest tetragonal distortion (c/a=1.064) and highest spontaneous polarization among perovskite titanates. But, it is hazardous and hence one needs to reduce Pb content by substituting or reducing Pb content for use in…

We investigated the temperature dependence of the superlattice intensity and thermal diffuse scattering intensity of BaAl2O4, which has a network structure with corner-sharing AlO4 tetrahedra, via synchrotron X-ray diffraction experiments.…

The structural, electrical transport and magnetic properties of perovskite oxides La1-xTexMnO3 have been investigated and thus the magnetic phase diagram of La1-xTexMnO3 compounds as a function of temperature and the doping level x has been…

The impact of ordered vacancies on the dynamic stability of perovskites is investigated under the $\textit{ab initio}$ framework with a focus on cubic BaFeO$_{3}$ ($Pm\bar{3}m$) and vacancy-ordered monoclinic BaFeO$_{2.67}$ ($P2_{1}/m$).…

Polycrystalline sample of (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3 was obtained by means of a conventional ceramic technology. The dielectric measurements were performed depending on temperature and frequency of electric measuring field.…

Using $\textit{ab-initio}$ crystal structure prediction we study the high-pressure phase diagram of $\textit{A}BiO_3$ bismuthates ($A$=Ba, Sr, Ca) in a pressure range up to 100$~$GPa. All compounds show a transition from the low-pressure…

Calcium stannate perovskite (CaSnO3) has been studied by Raman spectroscopy at two excitation wavelengths (514.5 nm and 632.8 nm). A new first-order order-disorder phase transition induces Raman frequency shifts and line width doubling at…

The halide double perovskite Cs$_2$AgBiBr$_6$ has been proposed as a potential replacement for organic halide perovskites for photovoltaic applications. Further investigation of its dielectric response, optical properties and structural…

The phonon spectrum of cubic BaThO$_3$ with the perovskite structure is calculated from first principles within the density functional theory. The analysis of unstable modes in the phonon spectrum enables to determine the symmetry of all…

The interplay between crystal electric field splitting of d states and Hund's rule exchange energy in cobalt-based perovskites offers a promising avenue for inducing spin-state transitions. This study reports a new body-centered tetragonal…

Neutron scattering investigations were carried out in PbMg$_{1/3}$Ta$_{2/3}$O$_3$ and BaMg$_{1/3}$Ta$_{2/3}$O$_3$ complex perovskites. The crystal structure of both compounds does not show any phase transition in the temperature range 1.5…

We report experimental studies of a series of BaFe$_2$S$_{3-x}$Se$_x$ ($0\leq x\leq3$) single crystals and powder specimens using x-ray diffraction, neutron diffraction, muon spin relaxation, and electrical transport measurements. A…

X-ray diffraction, dynamical mechanical analysis and infrared reflectivity studies revealed an antiferrodistortive phase transition in EuTiO3 ceramics. Near 300K the perovskite structure changes from cubic Pm-3m to tetragonal I4/mcm due to…

Group theoretical aspects of the three temperature-dependent and temperature-reversible experimentally observed phase transitions in the KNbO3 crystal (cubic-tetragonal, tetragonal-orthorhombic, orthorhombic-rhombohedral) in the framework…

The transition--metal oxide CaCu$_3$Ru$_4$O$_{12}$ with perovskite--type structure shows characteristic properties of an intermediate--valence system. The temperature--dependent susceptibility exhibits a broad maximum around $150 - 160$ K.…

While the tetragonal antiferro-electrically distorted (AFD) phase with space group $I4/mcm$ is well known for SrTiO$_3$ to occur below 105 K, there are also some hints in literature of an orthorhombic phase, either at lower temperature at…

In ABO3 perovskites, oxygen octahedron rotations are common structural distortions that can promote large ferroelectricity in BiFeO3 with an R3c structure [1], but suppress ferroelectricity in CaTiO3 with a Pbnm symmetry [2]. For many…