Electronic bonding characteristics of hydrogen in bcc iron: Part I. Interstitials
Electronic bonding characteristics of hydrogen in bcc iron: Part I. Interstitials
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DOI：
10.1557/jmr.1996.0280
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发表时间：
1996-09
影响因子：
2.7
通讯作者：
Y. Itsumi;D. Ellis
中科院分区：
文献类型：
--
作者：
Y. Itsumi;D. Ellis
采用局域密度泛函中的自洽离散变分方法（DV-X α），对bcc结构的铁团簇（Fe）在含氢和不含氢以及空位的情况下的电子结构进行了计算.研究表明：（1）间隙H显著降低了Fe-Fe原子间的键强度，但作用距离很小（0.3nm以内）; (ii)在理想Fe晶格场中，间隙H在任何位置都感受到排斥力。作为晶格弛豫的结果，可以预期体积膨胀。(iii)与空位结合的H优选从八面体位置向空位移动的位置。这与实验结果相当一致。
Electronic structure calculations were carried out for bcc iron (Fe) clusters with or without hydrogen (H), and also involving a vacancy, using the self-consistent Discrete Variational method (DV-X α ) within the local density functional formalism. Bonding characteristics investigated show the following: (i) Interstitial H notably decreases interatomic Fe–Fe bond strengths, but acts over a small distance (within 0.3 nm). (ii) In the perfect Fe lattice field, interstitial H feels a repulsive force at any site. As a result of lattice relaxation, volume expansion may be expected. (iii) H in combination with a vacancy prefers a position shifted from the octahedral site toward the vacancy. This is fairly consistent with an experimental result.