Dielectric Study on the Phase Transitions in Cs2ZnI4

Single crystals of cesium tetraiodozincate, Cs 2 ZnI 4 , were prepared, and the dielectric constants along the three crystallographic axes were measured below room temperature. As temperature decreases, the dielectric constant along the b -axis first increases, shows a change in the temperature derivative at 110 K, a λ-type peak at 102 K, and a discontinuous decrease around 90 K. These anomalies correspond to phase transitions.