First principles study on strain effect of hydrogen diffusion and dissolution behavior in Ruthenium

In this work, the role of three kinds of strain, such as volumetric, biaxial and shear strain, in the dissolution and diffusion of Hydrogen (H) in Ruthenium (Ru) were studied by using first-principles simulation method. It was found that under volumetric or biaxial strains, the dissolution energy of H in Ru increases with the increase of compressive strain and decreases with the increase of tensile strain. For shear strain, the effect of strain on the dissolution energy of H in Ru relies on the crystal plane to which the strain is applied. The diffusion coefficients of H in Ru are different along the c and a direction and strongly dependent on the type and value of strain. All above results indicate that, in comparison to strain-free Ru film, H aggregation and even H bubbles are more difficult to form in Ru film under compressive strain.