Thermodynamic investigations of BaUF6(s)

Abstract

The calcium fluoride solid electrolyte Galvanic cell: (-) Pt, U3O8(s) + UO2F2(s) + BaUF6(s) + BaF2(s) | CaF2(s) | NiO(s) + NiF2(s), Pt (+) was used to measure the standard molar Gibbs energy of formation of BaUF6(s). From the measured emf values of the cell and required Gibbs energy values from the literature, Δf G m° (T) of BaUF6(s) has been calculated. The pseudo-binary phase diagram of BaF2–UF4 system was calculated by minimization of Gibbs energies of the phases present in the system. The stability domain of BaUF6(s) has been calculated from the chemical potential diagram of Ba–U–F–O system at 800 K.