George W Woodruff School of Mechanical Engineering, Nuclear and Radiological Engineering Program, Georgia Institute of Technology, Atlanta, GA, USA.
J Phys Condens Matter. 2011 Oct 26;23(42):425402. doi: 10.1088/0953-8984/23/42/425402.
Hydrogen may be trapped in voids in iron, leading to undesirable material properties. In this paper, the energetics of small hydrogen-vacancy clusters in body centered cubic iron are investigated. Results from two interatomic potentials are compared. We use molecular dynamics and Monte Carlo methods to find the minimum energy configurations of voids of up to ten vacancies containing up to 50 hydrogen atoms with ratios of hydrogen to vacancy of 10 or less. The formation energies and binding energies of defects to these clusters are calculated. Our results indicate that the hydrogen stabilizes bubbles by causing vacancies to be more tightly bound to clusters, while neighboring irons are less tightly bound. Hydrogen itself becomes less well bound to clusters as the inventory increases. The more physically relevant potential indicates a maximum supported ratio of hydrogen atoms to vacancies of about 4.
氢可能被困在铁中的空隙中，导致不理想的材料性能。在本文中，研究了体心立方铁中氢空位团簇的能量学。比较了两种原子间势的结果。我们使用分子动力学和蒙特卡罗方法来找到最多包含 50 个氢原子的空位的最小能量配置，其中氢与空位的比例为 10 或更小。计算了缺陷对这些团簇的形成能和结合能。我们的结果表明，氢通过使空位更紧密地结合到团簇上来稳定气泡，而相邻的铁则结合得更不紧密。随着库存的增加，氢本身与团簇的结合变得不那么紧密。更符合物理实际的势表明，氢原子与空位的最大支持比例约为 4。
