Dielectric and Thermal Studies on New Phase Transition of CsHSeO4

The dielectric constant, specific heat and thermal expansion of CsHSeO 4 were measured as functions of temperature, and X-ray examination was also made. It was found that CsHSeO 4 undergoes a phase transition at 128°C. The crystal at room temperature is monoclinic with a space group P2/ c . The transition entropy was estimated from the specific heat to be Δ S =16.1 J·mol -1 deg -1 .