First-Principle of Adsorption Behavior of H Atom in PuGa Alloy

Abstract

PuGa alloy shows hydrogenation corrosive reaction exposed in a hydrogen atmosphere, which affects material microstructures and decreases the related performance. Considering the high toxicity and radioactivity of PuGa alloy, experimental conditions and technical constraints, it is difficult to study this project through experimental method. Therefore, first-principle simulations were applied to study the adsorption behavior of H atom in PuGa alloy and on (111) surface, which included the electronic structure of PuGa alloy and the adsorption process of H. Hydrogen atom prefers to adopt in tetrahedral-Pu3Ga site in PuGa bulk with an adsorption energy of -0.75 eV. In contrast, on the PuGa alloy (111) surface, hydrogen atom prefers to adopt in fcc/hcp-Pu3 site with the maximum absolute value of the adsorption energy of 0.62 eV. H atom has a lower diffusion barrier at the adjacent adsorption sites of Ga atom, especially a barrier energy less than 0.3 eV on the surface. In this study, the mechanism of H atom adsorption behaviors on the material surface is revealed in atomic scale, and can provide the theoretical support to reduce the influence of H on the material structures and properties.

Keywords

• puga alloy
• h atom
• adsorption behavior
• first-principlepu