Thermodynamic Stability of UMoO6 by the Transpiration Method

Abstract
The equilibrium vaporization of UMoO6(s) in dry air was studied by the transpiration method in the temperature interval 1110°≤ T (K) ≤ 1250°. Apparent pressure of the trimer measured over the two‐phase mixture UMoO6+ U3O8, with dry air as the carrier gas, was used to calculate the partial pressure of the trimer, (MoO3)3(g). In accordance with the vaporization reaction (UMoO6) = 1/3(U3O8) + 1/6(MoO3)3(g)+ 1/6O2 (g), the free energy of formation of UMoO6)(s) is given by (δ G° in kJ‐mol−1) δ G° (UMoO6) = (−1962 ± 10) + (0.463 ± 0.008) T