Stability and mobility of rhenium and osmium in tungsten; First principles study

Suzudo, Tomoaki   ; Yamaguchi, Masatake   ; Hasegawa, Akira*

We report a series of studies based upon density functional theory for the behavior of rhenium and osmium atoms in tungsten crystal. Contrary to the one-dimensional migration of self-interstitial atoms, interstitials of these solute elements in tungsten have three-dimensional motion. The diffusion of these solute elements strongly influences the effects of radiation upon the materials, and we found that the three-dimensional migration is a property that is key to the explanation of the radiation effects experimentally observed in tungsten-rhenium and tungsten-osmium alloys.