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论文类型： 期刊论文

发表时间： 2011-06-15

发表刊物： JOURNAL OF NUCLEAR MATERIALS

收录刊物： SCIE、EI

卷号： 413

期号： 2

页面范围： 90-94

ISSN号： 0022-3115

摘要： The stability and migration behavior of helium and self defects in vanadium and V-4Cr-4Ti alloy are studied by first-principles calculations. The tetrahedral site is found as the most stable configuration for interstitial He, followed by the octahedral and substitutional sites. Among the self defects, the mono-vacancy has lower formation energy (1.71 eV for V and 2.14 eV for V-4Cr-4Ti alloy) than the self interstitial ones. The migration energies for He hopping between the tetrahedral sites are 0.06 and 0.09 eV for vanadium and V-4Cr-4Ti alloy, respectively. Our calculations reveal strong repulsion between two interstitial He atoms and strong attraction between He and vacancy, suggesting that vacancy acts as a trapping site for He impurity and a seed for further bubble formation. (C) 2011 Elsevier B.V. All rights reserved.