ON THE DETERMINATION OF DIFFUSION-COEFFICIENTS IN MULTIPHASE TERNARY COUPLES

A methodology was presented for determining the interdiffusion coefficients of phases formed in a ternary diffusion couple using the measured growth rates and the concentration profiles across the couple. Using this methodology the interdiffusion coefficients of the T-Ni3GaAs phase were obtained from several GaAs/Ni couples. Assuming the cross-intrinsic diffusion coefficients to be negligible, relationships between intrinsic diffusion coefficients and interdiffusion coefficients were derived, and values were obtained for the three intrinsic diffusion coefficients of the T-phase. The intrinsic diffusivity for Ni was the largest and that for arsenic the smallest. These data were rationalized in terms of the structure of the T-phase.