Mass-Spectrometric Studies of the Gaseous Systems Au–Ni, Au–Co, and Au–Fe, and Dissociation Energies of AuNi, AuCo, and AuFe

The molecules AuX (X=Ni, Co, and Fe) have been shown to exist in the vapor phase over liquid solutions of gold and transition metals at temperatures above 1800°K. Using information derived from a combination of effusion and mass-spectrometric techniques, the equilibrium constants and energetics of the reactions AuX+Au=Au2+X have been determined. The dissociation energies of AuX, as obtained by the second-law method, are 58.0 ± 5, 50.4 ± 3, and 43.8 ± 4 kcal/mole for X equal to Ni, Co, and Fe, respectively.