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Title: Ab initio study of intrinsic, H and He point defects in hcp-Er

Abstract

Ab initio calculations based on density functional theory have been performed to determine the properties of self-interstitial atoms (SIAs), vacancies, and single H and He atoms in hcp-Er. The results show that the most stable configuration for an SIA is a basal octahedral (BO) configuration, while the octahedral (O), basal split (BS) and crowdion (C) interstitial configurations are less stable, followed by the split <0001> dumbbell and tetrahedral configurations. For both H and He defects, the formation energy of an interstitial atom is less than that of a substitutional atom in hcp-Er. Furthermore, the tetrahedral interstitial position is more stable than an octahedral position for both He and H interstitials. The hybridization of the He and H defects with Er atoms has been used to explain the relative stabilities of these defects in hcp-Er.

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
979493
Report Number(s):
PNNL-SA-70794
Journal ID: ISSN 0021-8979; JAPIAU; AT6020100; TRN: US201010%%719
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics, 107(5):Article Number: 054903; Journal Volume: 107; Journal Issue: 5
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATOMS; CONFIGURATION; CROWDIONS; DEFECTS; FUNCTIONALS; HYBRIDIZATION; INTERSTITIALS; POINT DEFECTS; VACANCIES; Ab initio calculations; helium; hydrogen; hcp-Er

Citation Formats

Yang, Li, Peng, SM, Long, XG, Gao, Fei, Heinisch, Howard L., Kurtz, Richard J., and Zu, Xiaotao T.. Ab initio study of intrinsic, H and He point defects in hcp-Er. United States: N. p., 2010. Web. doi:10.1063/1.3309834.
Yang, Li, Peng, SM, Long, XG, Gao, Fei, Heinisch, Howard L., Kurtz, Richard J., & Zu, Xiaotao T.. Ab initio study of intrinsic, H and He point defects in hcp-Er. United States. doi:10.1063/1.3309834.
Yang, Li, Peng, SM, Long, XG, Gao, Fei, Heinisch, Howard L., Kurtz, Richard J., and Zu, Xiaotao T.. Mon . "Ab initio study of intrinsic, H and He point defects in hcp-Er". United States. doi:10.1063/1.3309834.
@article{osti_979493,
title = {Ab initio study of intrinsic, H and He point defects in hcp-Er},
author = {Yang, Li and Peng, SM and Long, XG and Gao, Fei and Heinisch, Howard L. and Kurtz, Richard J. and Zu, Xiaotao T.},
abstractNote = {Ab initio calculations based on density functional theory have been performed to determine the properties of self-interstitial atoms (SIAs), vacancies, and single H and He atoms in hcp-Er. The results show that the most stable configuration for an SIA is a basal octahedral (BO) configuration, while the octahedral (O), basal split (BS) and crowdion (C) interstitial configurations are less stable, followed by the split <0001> dumbbell and tetrahedral configurations. For both H and He defects, the formation energy of an interstitial atom is less than that of a substitutional atom in hcp-Er. Furthermore, the tetrahedral interstitial position is more stable than an octahedral position for both He and H interstitials. The hybridization of the He and H defects with Er atoms has been used to explain the relative stabilities of these defects in hcp-Er.},
doi = {10.1063/1.3309834},
journal = {Journal of Applied Physics, 107(5):Article Number: 054903},
number = 5,
volume = 107,
place = {United States},
year = {Mon Mar 01 00:00:00 EST 2010},
month = {Mon Mar 01 00:00:00 EST 2010}
}
  • Ab initio calculations based on density functional theory have been performed to determine the relative stabilities and migration of H and He atoms in hcp-Sc. The results show that the formation energy of an interstitial H or He atom is smaller than that of a corresponding substitutional atom. The tetrahedral (T) interstitial position is more stable than an octahedral (O) position for both He and H interstitials. The nudged elastic band method has been used to study the migration of interstitial H and He atomss in hcp-Sc. It is found that the migration energy barriers for H interstitials in hcp-Scmore » are significantly different from those for He interstitials, but that their migration mechanisms are similar. In addition, the formation energies of five different configurations of a He-He pair were determined, revealing that the most stable configuration consists of two He atoms located at the second-neighbor tetrahedral interstitial sites along the c axis. The formation and relative stabilities of some small He clusters have also been investigated.« less
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