The thermodynamics of vacancy formation in f.c.c. metals

The dependence upon temperature of the monovacancy concentration in metals has been calculated using models for the perturbation of the atomic frequencies accompanying vacancy formation. The effect of the lattice thermal expansion has also been considered. The calculations, based on the quasi-harmonic model for solids, indicate that Arrhenius plots of the vacancy concentration against reciprocal temperature would exhibit a measurable curvature for Al. Much smaller degrees of curvature would be observable in such plots for Cu and Au over the temperature span of experimental vacancy concentration determinations.