High pressure structural phase transitions in CsCdCl3

Abstract

High pressure studies reveal two phase transitions for CsCdCl3 up to 125 kbar in the presence of traces of water. At ambient pressure, CsCdCl3 (phase I) is transparent and it transforms to an opaque phase II at 2.6 kbar. On further pressure increase to about 22 kbar, CsCdCl3 undergoes a second phase transition to another transparent phase (III). When water is absent, the opaque phase II cannot be observed; instead a transparent to transparent phase transition takes place below 12 kbar. These phase transitions are thought to be a series of transitions from a face-shared structure to a corner-shared structure. The transitions are reversible and very sluggish, in contrast to the irreversible phase transitions found in CsSnCl3. © 1994.