Growth of silicides in Ni-Si and Ni-SiC bulk diffusion couples

In this work, the integrated diffusion coefficient, D'-int' is used to describe the growth kinetics of silicides in Ni -Si and Ni-SiC diffusion couples. The integrated diffusion coefficients are determined from planar diffusion couple experiments for all intermetallic phases of the binary Ni-Si system between 1073 and 1173 K. For the growth of NisSi2 'an activation energy of 180 ± 30 kJjmol (1.9 ± 0.3 eV) was found. The position of the Kirkendall plane revealed that Ni is the only diffusing species in Ni3 Si and NisSi2. In NiSi2, Ni and Si are equally mobile. The activation energy for the interdiffusion in the Ni(Si) solid solution, measured between 1093 and 1423 K, is 250 ± 10 kJjmol (2.6 ± 0.1 eV) and is independent of the Si-concentration.