Thermodynamic and thermophysical properties of holmium orthovanadate

Abstract

The current paper reports thermodynamic and thermophysical property data on holmium orthovanadate over a wide temperature range. The heat capacities of HoVO4 have been measured using precision adiabatic calorimetry and differential scanning calorimetry over the temperature ranges of 7–343 K and 337–1097 K, respectively. A broad heat capacity anomaly, centred at 15 K, has been observed. The standard entropy of HoVO4 at 298.15 K, derived from low-temperature heat capacity data, has been estimated. This value, in conjunction with available thermodynamic data, has been used to evaluate the standard Gibbs energy of formation of HoVO4 from the elements. The temperature dependences of standard thermodynamic properties have been calculated from 0 K to 1100 K. Thermal diffusivity measurements for HoVO4 have been conducted from ambient temperature to 1073 K, using a laser flash method. The thermal conductivity has been evaluated on the basis of the heat capacity and thermal diffusivity data obtained.