Anisotropic strain enhanced hydrogen solubility in bcc metals: the independence on the sign of strain.
Anisotropic strain enhanced hydrogen solubility in bcc metals: the independence on the sign of strain.
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DOI：
10.1103/physrevlett.109.135502
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发表时间：
2012-09
影响因子：
8.6
通讯作者：
Hong-Bo Zhou;Shuo Jin;Ying Zhang;G. Lu;Feng Liu
中科院分区：
文献类型：
--
作者：
Hong-Bo Zhou;Shuo Jin;Ying Zhang;G. Lu;Feng Liu
当固体中掺杂杂质时，它不可避免地会引起局部应力，从而导致晶格膨胀或收缩。因此，可以施加应变来改变固体中杂质的溶解度。一般来说，溶解度对应变“单调”响应，如果杂质引起压应力，则溶解度随拉伸（压缩）应变增加（减少），反之亦然。然而，通过第一性原理计算，我们发现一些 bcc 金属中的各向异性应变可以增强 H 的溶解度，几乎与应变的符号无关。这种异常行为被发现是由各向异性应变引起的 H 位置连续变化引起的。我们的研究结果表明，bcc 金属中 H 气泡形成具有级联效应：H 溶液导致 H 气泡形成，从而诱发各向异性应变，进而增强 H 溶解度，进一步促进气泡生长。
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.