Systematic Variation of Diffusion Rates of Components in Silicides Depending on Atomic Number of Refractory Metal Component

Interdiffusion studies conducted in group IVB, VB and VIB metal-silicon systems are discussed in detail to show a pattern in the change of diffusion coefficients with the change in the atomic number of the refractory metal (M) component. MSi2 and M5Si3 phases are considered for these discussions. It is shown that integrated diffusion coefficients increase with the increase in the atomic number of the refractory component when the data are plotted with respect to the melting point normalized annealing temperature. This indicates the increase in overall defect concentration facilitating the diffusion of components. This is found to be true in both the phases. Additionally, the estimated ratios of tracer diffusion coefficients indicate the change in concentration of antisite defects in a certain manner with the change in an atomic number of the refractory components.