Defects and transport processes in beryllium
Defects and transport processes in beryllium
复制标题
DOI：
10.1016/j.actamat.2011.07.064
复制
发表时间：
2011-10-01
期刊：
影响因子：
9.4
通讯作者：
Grimes, R. W.
中科院分区：
文献类型：
--
作者：
Middleburgh, S. C.;Grimes, R. W.
本征和替代缺陷的形成和迁移能量铍金属已通过原子尺度的计算机模拟预测，并讨论了平衡和辐射损伤过程。肖特基无序被认为是占主导地位的本征缺陷过程，但它的高能量意味着只有一个小浓度的铍空位在晶格中。较高的反肖特基能量意味着本征间隙浓度仍将低几个数量级。Be空位和杂质迁移的能垒相似，分别为0.72和0.64 eV;两者基本上都是各向同性过程。计算了氢、氦、氧、铁、铝、碳、镁和硅的非本征缺陷性质。例如，氦具有大的正溶解能，但优先占据铍空位位置。相反，氧具有负溶解能，并且作为间隙物质最稳定。铁具有小的负溶解能，而铝和镁具有高的正溶解能。对关键金属间化合物FeBe（5）和FeAlBe（4）也进行了研究。(C)2011 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Intrinsic and substitutional defect formation and migration energies for beryllium metal have been predicted via atomic scale computer simulation and are discussed with respect to equilibrium and radiation damage processes. Schottky disorder was found to be the dominant intrinsic defect process, but its high energy implies only a small concentration of beryllium vacancies in the lattice. The anti-Schottky energy, being higher, implies that the intrinsic interstitial concentration will be still orders of magnitude lower. The energy barriers for migration of Be vacancies and interstitials are similar, at 0.72 and 0.64 eV respectively; both are essentially isotropic processes. Extrinsic defect properties have been calculated for hydrogen, helium, oxygen, iron, aluminium, carbon, magnesium and silicon. For example, helium has a large positive solution energy but preferentially occupies a beryllium vacancy site. Conversely, oxygen has a negative solution energy and is most stable as an interstitial species. Iron has a small negative solution energy, while aluminium and magnesium have high positive solution energies. The key intermetallics FeBe(5) and FeAlBe(4) have also been investigated. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.