Heat capacity and thermodynamic properties of some Ca silicides

The he;lt capacities of three Ca compounds, namely CaSi2, Ca3Si4 and Ca14Si19 were measured in the 3-300 K temperature range by adiabatic calorimetry. No thermal anomalies were found in the whole temperature range. La the three Ca Silicides. from an analysis of the low temperature data (T<40 K), a power law lower than three in the lattice heat capacity behaviour was observed and tentatively ascribed to the layered structure of the compounds, in agreement with structural informations. From heat capacity data the thermodynamic functions entropy, enthalpy and Gibbs energy were calculated at 298 K. (C) 2000 Elsevier Science S.A. All rights reserved.