Thermodynamic Study of Sb-Te Alloys by EMF Measurements Using Solid Zirconia Electrolyte

Abstract

The activity of Sb in liquid Sb−Te allloys and Gibbs free energy of formation of solid Sb 2 Te 3 were determined by the solid-state EMF technique using the following galvanic cells (Sb or Sb−Te), Sb 2 O 3 ∥O −2 ∥ air and (Sb 2 Te 3 + Te), Sb 2 O 3 ∥O −2 ∥ air. Thermodynamic properties of liquid Sb−Te solutions were described by ionic two-sublattice liquid model suggested by Hillert et al. [85Hil]. Gibbs free energy of formation of solid Sb 2 Te 3 from pure elements was derived for the reaction 2Sb(s) + 3Te(1) ⇔ Sb 2 Te 3 (s) from EMF measurements and available Sb−Te phase diagram in the following form ΔG 0 T = − 106260 + 60.11 . T [J.mol −1 ]