Adiabatic calorimetry and solid state properties above ambient temperature
Some developments in the use of adiabatic-shield calorimeters above ambient temperature are reported, with emphasis on their importance in the study of slow reactions. In addition to the usual demonstration of calorimeter performance in terms of the heat capacity of a-Al203, fractional enthalpy of fusion determinations as well as heat-capacity measurements on solid/solid transitions ought to be considered as testing experiments. In this connection results on indium and tin are presented. The larger variety of heat-capacity behavior in two- component systems are considered for solid/solid transitions in Ag2Se, quartz and cristobalite. The usefulnes of adiabatic calorimetry in the study of transitions from metastable to stable states is shown for the NiS phases and for wiistite.