The diffusion of Hf which was deposited onto a micro-crystal of W under ultra-high vacuum was investigated by using field emission density fluctuation methods. The diffusion coefficients were determined by analyzing experimental time auto-correlation functions for temperatures ranging from 370 to 470K. Surface diffusion activation energies of 0.53 to 0.54eV were obtained.

J.Beben, W.Gubernator: Surface Science, 1994, 304[1-2], 59-64