Activities in liquid Ga-Te alloys at 1120 k

Abstract

The activity of gallium in liquid Ga-Te alloys has been measured at 1120 K using a solid state galvanic cell incorporating yttria-stabilized thoria as the solid electrolyte. The cell can be schematically represented as (-) W,Re,Ga(1)+Ga₂O₃(s)|(Y₂O₃) ThO₂|Ga-Te(1) + Ga₂O₃(s), Re, W (+) The activity of tellurium was derived by Gibbs-Duhem integration. The activity of gallium shows negative deviation from Raoult's law for X_Ga < 0.6 and positive deviation from ideality for X_Ga > 0.6. The activity of gallium was constant in the composition range 0.73 < X_Ga < 0.89, indicating liquid state immiscibility in this region. The Gibbs energy of mixing and the concentration-concentration structure factor at long wavelength limit show a minimum at X_Ga ≈ 0.4, suggesting strong interactions in the liquid phase with formation of 'Ga₂Te₃'-type complexes.The Gibbs energy of mixing and the concentration-concentration structure factor at long wavelength limit show a minimum at X≈ 0.4, suggesting strong interactions in the liquid phase with formation of 'GaTe'-type complexes.