相关论文: The Structural Complexity of (Bi0.5Na0.5)TiO3-BaTi…

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.…

A first-principles study of the vibrational modes of PbTiO_3 in the ferroelectric tetragonal phase has been performed at all the main symmetry points of the Brillouin zone (BZ). The calculations use the local-density approximation and…

We performed X-ray diffraction and electrical resistivity measurement up to pressures of 5 GPa and the first-principles calculations utilizing experimental structural parameters to investigate the pressure-induced topological phase…

Our measured dielectric constant and mechanical response of multiferroic BiFeO3 indicate four phase transitions below room temperature. Features correlate with those reported at 50K (from a peak in the zero-field-cooled magnetic…

SrTiO3 is a textbook quantum paraelectric, with ferroelectricity purportedly suppressed by quantum fluctuations of ionic positions down to the lowest temperatures. The precise real space structure of SrTiO3 at low temperature, however, has…

The existing controversy about the room temperature structure of multiferroic Pb(Fe_1/2Nb_1/2)O_3 is settled using synchrotron powder x-ray diffraction data. Results of Rietveld refinements in the temperature range 300 to 12K reveal that…

Two novel room-temperature phase transitions are observed, via synchrotron x-ray diffraction and Raman spectroscopy, in the Pb(Zr0.52Ti0.48)O3 alloy under hydrostatic pressures up to 16 GPa. A monoclinic (M)-to-rhombohedral (R1) phase…

We report a molecular dynamics study of ab initio quality of the ferroelectric phase transition in crystalline PbTiO3. We model anharmonicity accurately in terms of potential energy and polarization surfaces trained on density functional…

In the present study, structural changes due to gradual doping of Sr in BaTiO3 were investigated by both x-ray and neutron powder diffraction techniques. Ba1-xSrxTiO3 (x=0.0, 0.5 and 1.0) samples were synthesized by PVA evaporation method…

We report a temperature-dependent neutron diffraction (ND) study on polycrystalline monoclinic BaIrO$_3$ which is famous for charge density wave (CDW) and weak ferromagnetic phase transitions at T$_C$$\sim$180 K simultaneously. A Rietveld…

We investigate the temperature-pressure phase diagram of BaTiO_3 using a first-principles effective-Hamiltonian approach. We find that the zero-point motion of the ions affects the form of the phase diagram dramatically. Specifically, when…

We report neutron inelastic scattering on single crystal 0.68Pb(Mg1/3Nb2/3O3)-0.32PbTiO3 (PMN-0.32PT), a relaxor ferroelectric material that lies within the compositional range of the morphotropic phase boundary (MPB). Data were obtained…

The prototypical phase change material GeTe shows an enigmatic phase transition at Tc ca. 650 K from rhombohedral (R3m) to cubic (Fm-3m) symmetry. While local probes see little change in bonding, in contrast, average structure probes imply…

Understanding the structural phase diagram of nano scale SrTiO3 has important implications on the basic physics and applications of the general class of transition metal oxide perovskites. Pressure dependent structural measurements on…

In order to explore the origin of the Metal-Insulator (M-I) transition, the precise crystal structures of the hole-doped Mott insulator system, Y1-XCaXTiO3 (x=0.37, 0.39 and 0.41), are studied for the temperature range between 20K and 300K…

Structure and dielectric characterization were performed on the (1-x)La(Mg1/2Ti1/2)O3 - xLa2/3TiO3 perovskite ceramics with the actual composition 0<=x<=0.52. The sequence of structure transformations was detected as x is increased: P21/n…

Measurements of the structure of hexagonal RMnO3 (R=rare earths (Ho) and Y) for temperatures significantly above the ferroelectric transition temperature (TFE) were conducted to determine the nature of the transition. The local and long…

Pulsed neutron diffraction investigations have been performed in the ferroelectric PZT system, Pb(Zr1-xTix)O3, doped with 1%wt. of Nb2O5, as a function of both temperature and composition. The study has been made in a wide range of…

The structural phase transformation in the La2/3Ba1/3MnO3 perovskite manganite was studied by ultrasound, neutron diffraction and electron microscopy techniques. Minima of the velocity and maxima of the decrement of the ultrasound point out…

According to x-ray diffraction (XRD) measurements, PbTiO$_3$ undergoes a phase transition from a tetragonal ferroelectric (FE) phase to a cubic paraelectric phase at 763 K. However, x-ray absorption fine-structure (XAFS) measurements…