Related papers: Structural heterogeneity and diffuse scattering in…
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 have studied structural phase transitions in high quality underdoped La$_{2-x}$Ba$_x$CuO$_4$ single crystals using high resolution x-ray scattering techniques. Critical properties associated with the continuous High Temperature…
TEM has shown that the strongly piezoelectric material Pb(Zr0.52Ti0.48)O3 separates into two phases at low temperatures. The majority phase is the monoclinic phase previously found by x-ray diffraction. The minority phase, with a nanoscale…
The variation in local atomic structure and chemical bonding of ZrHx (x=0.15, 0.30, 1.16) magnetron sputtered thin films are investigated by Zr K-edge (1s) X-ray absorption near-edge structure and extended X-ray absorption fine structure…
Soft phonons and diffuse scattering in insulating La$_{2-x}$Sr$_{x}$CuO$_4$ ($x=0.05$) have been studied by the neutron scattering technique. The X-point phonon softens from high temperature towards the structural transition temperature…
We report high $q$-resolution neutron scattering data on PMN-$x$PT single crystals with $x=20%$ and 27%. No rhombohedral distortion occurs in the 20PT sample for temperatures as low as 50 K. On the other hand, the 27PT sample transforms…
Neutron diffraction data obtained on single crystals of PbZr1-xTixO3 with x = 0.325 and x = 0.460, which lie on the pseudorhombohedral side of the morphotropic phase boundary, suggest a coexistence of rhombohedral (R3m/R3c) and monoclinic…
Polarized Raman, IR and time-domain THz spectroscopy of orthorhombic lead zirconate single crystals yielded a comprehensive picture of temperature-dependent quasiharmonic frequencies of its low-frequency phonon modes. It is argued that…
Results of Rietveld analysis of the synchrotron XRD data on Pb(Zr_xTi_1-x)O_3 (PZT) for 0.525\leqx\leq0.60 are presented to show the absence of rhombohedral phase on the Zr-rich side of the morphotropic phase boundary (MPB). Our results…
Evidences of a monoclinic phase in unpoled (PbMg1/3Nb2/3O3)1-x-(PbTiO3)x with x=0.35 (PMN-PT 35%) and unpoled (PbZn1/3Nb2/3O3)1-x-(PbTiO3)x with x=0.09 (PZN-PT 9%) are presented from a neutron Rietveld analysis. This monoclinic phase is…
Raman spectra of PbZr1-xTixO3 ceramics with titanium concentration varying between 0.40 and 0.60 were measured at 7 K. By observing the concentration-frequency dependence of vibrational modes, we identified the boundaries among…
Using molecular dynamics simulation, we study structural and dynamical heterogeneities at melting in two-dimensional one-component systems with 36000 particles. Between crystal and liquid we find intermediate hexatic states, where the…
A previously unreported ferroelectric phase has been revealed on a highly homogeneous sample of Pb(Zr0.52Ti0.48)O3 by high-resolution synchrotron x-ray powder diffraction measurements. At ambient temperature the sample has tetragonal…
High-pressure and variable temperature single crystal synchrotron X-ray measurements combined with first-principles based molecular dynamics simulations study diffuse scattering in the relaxor ferroelectric system PSN…
Barium zirconate BaZrO3 is one of few perovskites that is claimed to retain an average cubic structure down to 0K at ambient pressure, while being energetically very close to a tetragonal phase obtained by condensation of a soft phonon mode…
Recent cutting-edge experiments have provided {\it in situ} structure characterization and measurements of the pressure ($P$), density ($\bar{\rho}$) and temperature ($T$) of shock compressed silicon in the 100 GPa range of pressures and…
The PZT material near the morphotropic phase boundary where a monoclinic phase was observed is studied. A theory of the tetragonal to monoclinic phase transition was developed within the Landau free energy approach. The phase transition…
Ferroelectric phase transition in the semiconductor Sn2P2S6 single crystal has been studied by means of neutron scattering in the pressure-temperature range adjacent to the anticipated tricritical Lifshitz point (p=0.18GPa, T=296K). The…
The relaxor ferroelectric PbMg_1/3Ta_2/3O_3 was studied by single-crystal neutron and synchrotron x-ray diffraction and its detailed atomic structure has been modeled in terms of static Pb-displacements that lead to the formation of polar…
The results are presented of anelastic and dielectric spectroscopy measurements on large grain ceramic PZT with compositions near the two morphotropic phase boundaries (MPBs) that the ferroelectric (FE) rhombohedral phase has with the…