The thermal capacity and enthalpy of gadolinium sesquiselenide over a wide temperature range

Measurements have been made on the thermal capacity of gamma-Gd2Se3 at 58.88-298.34 K. Values have been obtained for the thermal capacity, entropy, reduced Gibbs energy, and enthalpy under standard conditions: Cp deg = 125.87 plus/minus 0.5 J x mole-l x K(-l); S deg (298.15K) = 196.5 x 1.6 J mole(-l) x K(-l); Phi deg (298.15K) = 103.6 plus/minus 1.6 J x mole(-l) x K(-l); H deg (298.15 K) - H deg (0) = 27681 plus/minus 138 J x mole(-l). The enthalpy of Gd2Se3 has been measured and the major thermodynamic functions have been calculated for the solid and liquid states over the temperature range 450-2300 K. The temperature dependence of the enthalpy in the ranges 300-1800K and 2000-2300K are represented: H deg (T) - H deg (298.15 K) = 1.1949 x 10(-2) x T(2) + 122.38 x T + 347402 x T(-l) - 38716 and H deg (T) - H deg (298.15 K) = 262.81 x T -196047, respectively. The calculated temperature, enthalpy, and entropy of melting for Gd2Se3 are: Tm = 1925 plus/minus 40 K, DeltamH deg (Gd2Se3) = 68.5 kJ x mole(-l), DeltamS deg (Gd2Se3) = 35.6 J x mole(-l) x K(-l).