TEMPERATURE DEPENDENCE OF THE THERMODYNAMIC PARAMETERS OF COBALT(II) CLATHROCHELATE: X-RAY DIFFRACTION AND CALORIMETRIC CHARACTERISTICS OF THE LOW TEMPERATURE STRUCTURAL PHASE TRANSITION
I. E. Paukov, Y. A. Kovalevskaya, V. I. Ovcharenko, G. V. Romanenko, Y. Z. Voloshin
Keywords: cobalt(II), clathrochelates, low temperature calorimetry, heat capacity, phase transition
Pages: 386-390
Abstract
The temperature dependence of heat capacity of the polycrystalline sample of cobalt(II) clathrochelate in a range of 6-300 K is studied. Based on the smoothed dependence Cp(Т), the entropy and enthalpy values in a temperature range of 8-300 K and their standard values at 298.15 K are calculated. In the Cp(Т) curve in a range of 50-70 K, a process is recorded whose entropy and enthalpy are 1.2 J·(K·mol-1) and 68 J·mol-1 respectively. A comparison of the results with the data of a multitemperature X-ray diffraction study makes it possible to attribute this process to the structural phase transition.
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