Thermodynamic Description of Heat Capacities in Nonstoichiometric Phases

Abstract

The number of technical applications utilizing some unique properties of nonstoichiometric phases (ferrites, superconducting cuprates, metal hydrides) is gradually increasing. For further development of materials chemistry it is therefore important to know the detailed thermodynamic description of the phases. This knowledge helps optimize the preparation of nonstoichiometric phases and determine their stability limits. This review presents relations for calculation of heat capacity, thermal expansion and compressibility of nonstoichiometric phases. Furthermore, expressions for the dilation contribution to heat capacity are derived and discussed.