Effect of temperature on diffusion behavior of Te into nickel

The diffusion behavior of tellurium into pure nickel is investigated at different annealing temperatures. The purpose is to understand the diffusion mechanism of Te by studying the influence of Te on the surface morphology and grain boundary of nickel. The results show that the surface morphology, reaction product and penetration of Te are greatly dependent on annealing temperature. The depth of Te penetration increases with the elevated temperature from 500 °C to 1000 °C, and the surface reaction products is NiTe0.67 (Ni3Te2) or mixture of a spot of NiTe0.69. Te diffuses into nickel predominantly along the grain boundary at low temperature (below 900 °C), while the diffusion mechanism of Te turns to lattice diffusion above 1000 °C.