Heat capacity and thermodynamic properties of FeSb2 from 5 to 1021.2 K Enthalpy of decomposition

Abstract

The heat capacity of FeSb2 has been measured by adiabatic-shield calorimetry from 5 to 1021.2 K. At the latter temperature the phase decomposes into the FeSb phase and an antimony-rich melt. The heat capacity increases regularly over the entire temperature range, except for a high value at 898 K which is related to the fusion of a small amount of antimony. The enthalpy of peritectic decomposition of FeSb2 at 1021.2 K is (12910 +/- 30) calth mol-1. Thermodynamic functions have been evaluated and the values of Cp, {So(T) - So(0)}, and -[{Go(T) - Ho(0)}/T] at 298.15 and 1000 K are 19.08, 25.98, 12.881, and 24.80, 51.01, and 32.25 calth K-1 mol-1, respectively. The present results together with the Gibbs free energy of formation values from the literature give the formation values: