DSC STUDY OF THE PHASE-TRANSITIONS IN [NI(D2O)(6)](CLO4)(2) AND [NI(H2O)(6)](CLO4)(2)

DSC measurements were carried out for [Ni(H2O)(6)](ClO4)(2) (sample H) and [Ni(D2O)(6)](ClO4)(2) (sample D) in the temperature range 300-380 K. For both compounds two anomalies on the DSC curves were detected. The results for sample Hare compared to those previously obtained using adiabatic calorimetry method. For both compounds studied in this work the high-temperature transition appears at the same temperature while the low-temperature one is shifted towards higher temperatures in sample D. Disorder connected with H2O or D2O groups is suggested in the intermediate phase between the low- and high-temperature transitions.