High pressure phase transition studies of CsSnCl3

Abstract

The phase transitions of CsSnCl3 have been investigated by Raman scattering and optical observations under high pressure up to 60 kbar in a diamond anvil cell. Two new high pressure phases have been discovered. The first phase transition II/III is first order and occurs at 3.3 kbar. It is marked by the softening of the ν1 mode of the SnCl- 3 ion and dramatic spectral changes for all the Raman bands. The second transition III/IV is also first order and occurs at 25.3 kbar. This phase transition is manifested by the disappearance of all the Raman peaks in phase IV. In this phase, the molecules are more closely packed than in the monoclinic phase II. The ν1 mode which is at 296 cm-1 for the free SnCl- 3 ion appears as a strong Raman peak at 167 cm-1 for CsSnCl3 phase II. © 1994.