Determination of the standard Gibbs free energy of the intermetallic compound Ni3Al in the temperature range (820 to 920) K by a solid-state galvanic cell method

Abstract The standard Gibbs free energy of formation of the intermetallic compound Ni 3 Al and the aluminium activity have been determined in the temperature range (820 to 920) K with the help of solid-state galvanic cells involving calcium fluoride as an electrolyte. The behaviour of the molar Gibbs free energy of mixing for Ni 3 Al at 900 K plotted as a function of the mole fraction of Ni, along with those determined previously for other intermetallic compounds in the Ni–Al system, indicates consistency of all the data obtained.