Stress effects on stability and diffusion of H in W: A first-principles study

We perform first-principles calculations to investigate the stress effects on stability and diffusion of H in W. Both the solution energy and the diffusion barrier of H decrease with increasing tensile stress. We show that the stress will not alter the site preference and the relative stability, with ∼0.4 eV stress-independent energy difference between the TIS and the OIS. We demonstrate the solution and the diffusion of H in W becomes more difficult under the applied compressive stress, which theoretically provides a possible way to suppress the H retention in W.