Interdiffusion and the phase boundary compositions in the Co–Ta system

Diffusion parameters such as the interdiffusion coefficients and the ratio of the tracer diffusion coefficients are calculated in the Co2Ta Laves phase. The activation energy for the interdiffusion coefficients is calculated as 186 ± 29 kJ/mol. The ratio of tracer diffusion coefficients indicates that Co has higher diffusion rate than that of Ta. This is explained with the help of possible point defects and the crystal structure of the phase. The phase boundary compositions measured in this study is different from the compositions published previously.

► Interdiffusion study is conducted in the Co–Ta system. ► The phase boundary compositions are determined. ► Interdiffusion coefficient in the Co2Ta and the ration of tracer diffusivities are determined. ► Co is faster diffusing species in the Co2Ta phase.