Electromotive force measurements in liquid K–Te solutions with a potassium β alumina electrolyte

Thermodynamic properties and phase relations of K–Te alloys were measured over a temperature range of 573–873 K and over the composition range 0–55 at. % K. An electromotive force (emf) technique was used in which potassium-substituted beta alumina served as the solid electrolyte. Partial and integral values of Gibbs energy, entropy, enthalpy, excess stability, and excess heat capacity are reported. The excess stability function exhibits maxima near 12 and 50 at. % K which can be interpreted as an indication of maximum short-range ordering near these compositions. Liquidus points on the phase diagram are also reported as are the Gibbs energies of formation of the compounds K2Te3 and KTe.