Preparation, characterization and thermodynamic stability of Rh3Te2O10

A new ternary compound Rh3Te2O10 was synthesized by reacting Rh2O3 and TeO2 under 1 bar oxygen at 950 K. The compound was characterized by TG-DTA, XRD, EDX and magnetic susceptability analyses. From the TG experiment, the formation reaction could be expressed as 6Rh2O3(s) + 8TeO2(s) + 3O2(g) = 4Rh3Te2O10(s). Rh3Te2O10 crystallizes with a rutile type structure, a = 456.6(2), c = 385.9(1) pm, space group P42/mnm (No. 136). The thermodynamic stability of the compound was determined by measuring the vapor pressure of TeO2(g). The vapor pressure over the two-phase mixture of Rh2O3 and Rh3Te2O10 is given by the relation ln p(TeO2)/Pa (±0.07) = −36138.9 · T−1 + 35.3, 915 ⩽ T/K ⩽ 985. The Gibbs energy of formation of the compound derived using the above vapor pressure data can be expressed as ΔfG°(Rh3Te2O10, s) (±7.0 kJ mol−1) = −1510.3 + 0.897 T, 915 ⩽ T/K ⩽ 985.