HIGH-TEMPERATURE AND HIGH-PRESSURE RAMAN-STUDY OF LIVO3

We investigate the vibrational behavior of LiVO3 in the pyroxene struc ture, C2/c, using Raman spectroscopy at high temperature and high pres sure. With increasing temperature, no phase changes are observed. Upon pressurizing, we find three phase transitions at 20, 45 and 65 kbar. The third phase transition is associated with the break-down of the ch ain structure. We discuss a possible mechanism for pyroxene-ilmenite o r pyroxene-LiNbO3-type displacive transformations.