MEASUREMENT OF THE HEAT-CAPACITY OF BAEU2MN2O7

The heat capacities of non-stoichiometric BaEu2Mn2O7 phase were measured from room temperature to 850 K using differential scanning calorimetry. In stoichiometric BaEu2Mn2O7, a thermal anomaly caused by the crystallographic phase transition was observed. The transition temperature was 565 K and the enthalpy change was determined to be 2.28 kJ mol-1. It was found that the values of the heat capacity, except for in the vicinity of the transition temperature, were not greatly affected by non-stoichiometry and were larger than the maximum heat capacity which is predicted from the Dulong-Petit law.