Successive phase transitions in tetra(isopropylamine)decachlorotricadmate (II) [(CH3)2CH NH3]4Cd3Cl10] crystal – Dielectric and dilatometric studies

Single crystal of a new [(CH3)2CHNH3]4Cd3Cl10 compound was grown and its properties have been characterized by dielectric and dilatometric investigations. Dielectric measurement evidenced the phase transitions at T1 = 352.8 K, T2 = 293.5 K and T3 = 261.5 K on cooling run. Dilatometric measurement of thermal expansion showed clearly two successive phase transitions at T1 and at T2. No temperature hysteresis was observed for phase transitions at T1 and T2. Large temperature hysteresis was observed at T3 in dielectric studies. Transitions at T1 and T3 are classified as a first order and at T2 as a continuous one. Anomalies of electric permittivity and expansion connected with the transitions are observed at practically the same temperatures and close to those observed earlier in DSC (Differential Scanning Calorimetry) studies. Results of dilatometric studies were applied to estimate critical coefficient β for continuous phase transition at T1 which is equal to 0.40 ± 0.01.