Thermodynamics of uranium intermetallic compounds II. Heat capacity of UPd 3 from 8 to 850 K

Abstract

The heat capacity (from 8 to 350 K) of UPd 3 by adiabatic calorimetry and (from 400 to 900 K) by enthalpy-increment drop calorimetry has been measured and the thermodynamic properties at 298.15 K have been evaluated as C p, m R = 12.28 , Δ 0 TS m o R = 21.21 , Δ 0 TH m o (R · K) = 2817 , and Φ m o R = 11.76 . Our results agree with the interpretation of localized electrons with discrete energy levels and resultant Schottky contributions. The excess of heat capacity we found over the lattice and electronic contributions is compared with the theoretical values calculated from the crystal-field model proposed by Murray and Buyers. Confirmation that the conduction-electron contribution is small can be deduced from our results and this conclusion is in accord with other interpretations.