Knudsen cell - mass spectrometry for the determination of the thermodynamic properties of liquid copper—nickel alloys

Abstract

The Analytical Intensity-Ratio Method has been applied for the determination of the thermodynamic properties of liquid CuNi alloys by means of Knudsen cell mass spectrometry. The excess Gibbs energies G E and the heats of mixing H E are positive over the whole range of compositions. At 1750 K the maximum value of G E is 3515 J/mol (51.4 at% Ni) and the maximum value of H E is 2915 J/mol (53.8 at% Ni). The excess entropies S E are negative over the whole concentration range, with a minimum value of −0.367 J/mol K at 40.5 at% Ni. The thermodynamic activities show positive deviations from Raoult's Law.