Nonstoichiometry and Defect Mechanism in Intermetallics with L12-Structure

Abstract

ABSTRACTA statistical-thermodynamic model was derived which allows to describe thermodynamic activities in intermetallic compounds with L12-structure as a function of composition and temperature. The energies of formation of the four types of point defects (anti-structure atoms and vacancies on both sublattices) were used as adjustable parameters. The model was applied to the three compounds Ni3Al, Ni3Ga, and Pt3Ga, and it permitted to estimate for the first time the defect formation energies for Ni3Ga and to provide initial estimates for Pt3Ga.