铝中氢扩散的第一性原理理论

First-principles theory of hydrogen diffusion in aluminum.

作者信息

Gunaydin Hakan, Barabash Sergey V, Houk K N, Ozoliņs V

机构信息

Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.

出版信息

Phys Rev Lett. 2008 Aug 15;101(7):075901. doi: 10.1103/PhysRevLett.101.075901.

DOI:10.1103/PhysRevLett.101.075901

PMID:18764553

Abstract

Ab initio molecular dynamics simulations are used to obtain the activation enthalpy and preexponential factor for the lattice diffusion of hydrogen in aluminum between the temperatures 650 and 850 K: DeltaH double dagger=0.12+/-0.02 eV and D0=1.8 x 10(-7)m2/s. Vacancies are found to significantly decrease the apparent diffusivity due to their ability to bind one, two, or even six hydrogen atoms, causing a strong composition dependence and non-Arrhenius behavior of the effective diffusion coefficient.

摘要

采用从头算分子动力学模拟来获得氢在铝中于650至850 K温度范围内晶格扩散的活化焓和指前因子：ΔH‡ = 0.12±0.02 eV，D0 = 1.8×10−7 m2/s。发现空位会显著降低表观扩散率，因为它们能够结合一个、两个甚至六个氢原子，导致有效扩散系数具有强烈的成分依赖性和非阿累尼乌斯行为。