Heat capacity and thermodynamic properties of triuranium silicide from 1 to 1203 K

Abstract The heat capacity of triuranium silicide, U 3 Si, has been measured from 1 to 350 K and its enthalpy determined from 298 to 1160 K. The coefficient γ for the heat capacity contribution of the conduction electrons ( γT ) is (39.3 ± 0.4) mJ K −2 mol −1 . Thermodynamic functions are tabulated at selected temperatures between 1 and 1203 K. At 298.15 K, the values determined for the heat capacity C p o , the entropy S o , the enthalpy { H o (298.15 K) − H o (0)}, and the function {G o (298.15 K ) − H o (0)} 298.15 K are (107.90 ± 0.43) J K −1 mol −1 , (174.02 ± 0.70) J K −1 mol −1 , (23297 ± 93) J mol −1 , and −(95.88 ± 0.38) J K −1 mol −1 , respectively. The standard Gibbs energy of formation ΔG f o (U 3 Si, c, 298.15 K) = −(105.6 ± 19.2) kJ mol −1 was derived.