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arXiv 1204.4512cond-mat.mtrl-sci
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氢在Pd-Cu合金中渗透的第一性原理模拟

First-principles based modeling of hydrogen permeation through Pd-Cu alloys

Lin Qin, Chao Jiang

摘要:

采用第一性原理计算、成分依赖局域团簇展开(CDLCE)技术和动力学蒙特卡罗模拟相结合的方法研究了氢在无序Pd 1-xCux合金中的溶解度和扩散系数.我们表明,线性CDCLE模型已经可以准确地描述间隙H在Pd 1-xCux合金在整个组成范围内(0 \leqx \leq 1)的准确度与直接第一性原理计算。我们预测的H溶解度和渗透率的结果是在合理的协议与实验测量。所提出的模型是相当普遍的,可以用来快速,准确地筛选大量的合金组合物的潜在膜应用。扩展到三元或更高阶合金系统应该是直接的。我们的研究还强调了局部晶格弛豫对尺寸失配无序合金中H能量学的显著影响,这在文献中很大程度上被忽视了。

英文摘要:

The solubility and diffusivity of hydrogen in disordered Pd1-xCux alloys are investigated using a combination of first-principles calculations, a composition-dependent local cluster expansion (CDLCE) technique, and kinetic Monte Carlo simulations. We demonstrate that a linear CDCLE model can already accurately describe interstitial H in Pd1-xCux alloys over the entire composition range (0\leqx\leq1) with accuracy comparable to that of direct first-principles calculations. Our predicted H solubility and permeability results are in reasonable agreement with experimental measurements. The proposed model is quite general and can be employed to rapidly and accurately screen a large number of alloy compositions for potential membrane applications. Extension to ternary or higher-order alloy systems should be straightforward. Our study also highlights the significant effect of local lattice relaxations on H energetics in size-mismatched disordered alloys, which has been largely overlooked in the literature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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