Sodium uranium(V) trioxide, NaU03: heat capacity and thermodynamic properties from 5 to 350 K

The heat capacity of a sample of NaUO3 was determined in the temperature range 5 to 350 K by aneroid adiabatic calorimetry. The heat capacity at constant pressure Csub(p)sup(o)(298.15 K), the entropy Ssup(o)(298.15 K), the enthalpy (Hsup(o)(298.15 K) - Hsup(o)(O)) and the function -(Gsup(o)(298.15 K) - Hsup(o)(O))/298.15 K were found to be (108.87 +- 0.11)J K-1 mol-1, (132.84 +- 0.13) J K-1 mol-1, (20176 +- 20) J mol-1, and (65.17 +- 0.06) J K-1 mol-1, respectively. A non-isothermal peak in the heat capacity, probably correlated with magnetic ordering, was noted at (31 +- 1) k. (author)