Diffusion in L1(2) type intermetallic compounds

Discussion on diffusion mechanisms of intermetallic compounds requires the values of the self-diffusion coefficients of the constituent elements. Such data for the Lit compounds have recently become available for Ni3Ge and Ni3Ga. For Ni3Al, the self-diffusion coefficient of Al can be estimated from the interdiffusion coefficient and the tracer diffusion coefficient of Ni. The ratio of the diffusion coefficients D-B/D-A (A = Ni, B = Al, Ga, Ge) are: 0.8-1.3 (Ni3Al), 0.43 (Ni3Ga) and 0.007 (Ni3Ge) at T/T-m = 0.85. Possible mechanisms of diffusion in the L1(2) compounds are discussed.