Thermodynamic properties of silicides. II. Heat capacity at temperatures T from 5.9 K to 341 K and derived thermodynamic properties to T = 1200 K of tungsten disilicide: WSi2.06

Abstract

The heat capacity of tungsten disilicide WSi2.06 was measured over the temperature range 5.9T/K)-2[middle dot]mol-1. For the lattice, the Debye characteristic temperature [Theta]CD = (317.8+/-3.3) K. From our results, the standard molar entropy Som (WSi2.06, cr, 298.15 K) = (68.43+/-0.17) J[middle dot]K-1[middle dot]mol-1. On the basis of this result, the standard molar Gibbs free energy of formation [Delta]fGom(WSi2.06, cr, 298.15 K) = -(79.5+/-5.5) kJ[middle dot]mol-1. Heat capacities derived from drop calorimetry at T = 460 K together with those reported in this work allowed standard molar thermodynamic functions to be presented at selected temperatures from 5 K to 1200 K.