作者:G. A. Sharpataya、K. S. Gavrichev、A. V. Khoroshilov、V. N. Plakhotnik
DOI:10.1023/b:inma.0000020533.36731.ac
日期:2004.3
The heat capacity of rubidium hexafluoroarsenate, RbAsF6, was measured from 300 to 700 K by differential scanning calorimetry. The results indicate that the structural transformation from the rhombohedral to the cubic phase occurs in the range 305-436 K through an intermediate stable phase and reaches isothermal completion in a narrow temperature range of 407-409 K. The enthalpy of the transformation is 10.90 0.03 kJ/mol, and its entropy is 26.39 +/- 0.08 J/(K mol) = Rln24, which suggests that this structural transition is of the order-disorder type. The heat capacity data are used to evaluate the thermodynamic properties of RbAsF6 in the range 300-700 K.