Activity of Gallium in NiGa and Associated Gallium-Gallium Oxide Equilibria

The relative partial molal free energy of gallium and the activity of gallium in the compound NiGa have been obtained across the homogeneity range of this phase at 835° and 900°C. A solid state anion conductor ( CaO ‐ stabilized ZrO 2 ) was used as the electrolyte in a high temperature galvanic cell. It was found that the thermodynamic properties of NiGa change rapidly near 50 atom per cent gallium. A brief review is made of the metal/oxide equilibria and the free energies of the two gallium oxides Ga 2 O 3 and Ga 2 O .