title: Anisotropic strain enhanced hydrogen solubility in bcc metals: the independence on the sign of strain.
abstract: When an impurity is doped in a solid, it inevitably induces a local stress, tending to expand or contract the lattice. Consequently, strain can be applied to change the solubility of impurity in a solid. Generally, the solubility responds to strain "monotonically," increasing (decreasing) with the tensile (compressive) strain if the impurity induces a compressive stress or vice versa. Using first-principles calculations, however, we discovered that the H solubility can be enhanced by anisotropic strain in some bcc metals, almost independent of the sign of strain. This anomalous behavior is found to be caused by a continuous change of H location induced by anisotropic strain. Our finding suggests a cascading effect of H bubble formation in bcc metals: the H solution leads to H bubble formation that induces anisotropic strain that in turn enhances H solubility to further facilitate bubble growth.
authors.affiliation: Department of Physics, Beihang University, Beijing 100191, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Zhou
authors.forename: Shuo
authors.initials: S
authors.lastname: Jin
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guang-Hong
authors.initials: GH
authors.lastname: Lu
authors.forename: Feng
authors.initials: F
authors.lastname: Liu