Calorimetric Observations of Phase Transitions in Cs₂CdBr₄ Crystal

Abstract

First precise measurements of specific heat changes were performed for the Cs₂CdBr₄ crystal using the ac calorimeter. Phase transitions at about 152 K, 236 K and 252 K were revealed. The continuous second order phase transition at 252 K to the incommensurate phase is described by the 3D XY model. Thermal parameters (as the excess enthalpy ΔH, and the excess entropy ΔS) of continuous transitions were estimated and discussed. We noted in unrecurring way an additional anomaly at about 208–212 K and 130 K that could be connected with previously reported transitions.

Keywords:

• Heat capacity
• incommensurate phase
• ferroelastics

Acknowledgements

This work was supported by the University of Wroclaw (grant 2016/W/IFD/2003).