A sequence of structural/magnetic transitions on cooling is reported in the literature for hole-doped iron-based superconductor (Ba1 − xKx)Fe2As2 with x = 0.24. By using polarized light microscopy, we directly observe the formation of orthorhombic domains in (Ba1 − xKx)Fe2As2 (x = 0.24) single crystal below a temperature of simultaneous structural/magnetic transition TN ~80 K. The structural do...

A set of critical conditions for the characteristic caustic points in the phonon focusing patterns in tetragonal crystals is formulated. A caustic line segment in the focusing pattern is generally associated with either a fold or a cusp on the wave surface. Most of the caustic lines are symmetrical with respect to the principal symmetry plane and can be characterized by the caustic points at th...

We investigate by angle-resolved photoemission the electronic structure of in situ grown tetragonal CuO, a synthetic quasi-two-dimensional edge-sharing cuprate. We show that, in spite of the very different nature of the copper oxide layers, with twice as many Cu in the CuO layers of tetragonal CuO as compared to the CuO(2) layers of the high-T(c) cuprates, the low-energy electronic excitations ...

Tungsten trioxide (WO3) nanobelts in tetragonal structure were grown on Si substrates by a hot-wall chemical vapor deposition (CVD) method without using catalysts. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, and photoluminescence (PL) spectrum. The width of the nanobelts is in the ran...

NMR and high-resolution x-ray diffraction of several lithium-doped fullerides LixC60 show that the stoichiometry x512 represents a stable Li doping for a high symmetry C60-like phase, which might extend to much larger x. Li12C60 is fcc at high temperature, and it distorts to tetragonal upon cooling. We have evidence from C NMR that the C60 units are static in the tetragonal phase at least up to...

High permittivity barium titanate zirconate (BTZ) is often used for dielectrics in commercial multilayer ceramic capacitors, actuators applications, and is a highly promising material for dynamic random access memory (DRAM) and microelectromechanical system (MEMS) applications due to its very stable, high insulating characteristic against voltage. Especially, the material is promising for envir...

Samples of 0.96(K0.48Na0.48Li0.04)(Nb0.95Sb0.05)O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 piezoelectric ceramic were fabricated with conventional techniques and sintered at different temperatures. The effect sintering temperature (TS) on the structure, microstructure, properties ceramics was studied in detail. experimental results showed that an increase TS temperature, structure transformed from orthor...

In this paper we report on the deposition of La0.99Ca0.01NbO4 thin films with scheelite-type crystal structure. Thanks to the film's nanostructure, we were able to stabilize the tetragonal scheelite-type structure phase at room temperature, which involves a full removal of the fergusonite-scheelite phase transition.

The structure of the high-temperature scheelite-type polymorph of cerium niobium tetraoxide, CeNbO(4), has been determined using time-of-flight neutron powder diffraction data collected both in situ at 1073 K in air and in vacuo. In both cases, the structure was found to be tetragonal, with I4(1)/a symmetry and without any significant deviation from the stoichiometric composition.