Stability of K2CrO4 to 50GPa using Raman spectroscopy measurements

摘要

Raman spectroscopic measurements of K2CrO4 upon compression in an argon pressure medium reveal a series of structural transitions between ambient conditions and 50 GPa. The solid remains crystalline to the highest pressure measured. This behavior is consistent with an emerging trend upon compression for the extended class of A(2)BX(4) solids which are isostructural to K2CrO4. In particular crystals with size ratios of anionic tetrahedral BX4 groups to interstitial A cations below 1.45 remain crystalline at all pressures examined whereas those having ratios higher than 1.45 become amorphous. (C) 2004 Elsevier Inc. All rights reserved.