High temperature and high pressure Raman study of LiVO3

Structural Disorder and Ionic Conductivity in LiVO3: A Neutron Powder Diffraction Study from 340 to 890 K

“…This peculiar behavior, observed on both sites, suggest a positional disorder of the Li> cations along the c-axis. Such a disorder was already proposed from hightemperature Raman spectroscopy studies by Grzechnik et al (17). The band observed at 185 cm\ was assigned to the Li}O motions increasing with the temperature, suggesting an enhancement of the thermal disorder especially on the Li(2) site.…”

High Pressure Behavior of Sr3(VO4)2and Ba3(VO4)2

“…Further investigations of these materials at high pressure will be required using X-ray diffraction to fully elucidate the mechanisms of the structural change. The first order phase change and associated hysteresis noted in Sr (VO ) is a promising result for obtaining new families of these materials by high pressure synthesis (12,13).…”

“…8). It is of interest that the broad but well-defined band in the spectrum of Ba (VO ) at high pressure occurs at 800 cm\, which the frequency observed for the high pressure phase of LiVO in the LiNbO structure, containing cornerlinked VO groups (12,13). However, the structural change does not occur homogeneously throughout the sample, because the Ba (VO ) spectrum is still dominated by both the tetrahedral V-O stretching and the O-V-O bending modes of the ambient pressure orthovanadate phase (Figs.…”

“…The purpose of the present study is to begin to explore the potential of high pressure methods for preparation of new compounds in the orthovanadate systems. As in our previous studies, it was useful to begin with an investigation of the phase transformations occurring in the pure compounds at high pressure and during their decompression path (12). The phase transitions and structural distortions are conveniently followed by Raman spectroscopy, carried out in situ in the diamond anvil cell (16 .…”

“…Luminescence in these compounds is largely determined by point defects in the crystal structure. We have recently investigated the use of high pressure in formation of quenchable metastable oxides with the perovskite and lithium niobate structures (12)(13)(14)(15). The purpose of the present study is to begin to explore the potential of high pressure methods for preparation of new compounds in the orthovanadate systems.…”