Atomic relaxations around vacancy clusters in molybdenum and their effects on trapped-positron lifetime

S. N. Khanna*, B. K. Rao, P. Jena, D. Esterling, M. J. Puska

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

12 Citations (Scopus)
178 Downloads (Pure)

Abstract

The relaxations of first- and second-nearest-neighbor shells of atoms around a monovacancy and around voids corresponding to the removal of 9, 15, 27, and 51 atoms in molybdenum have been calculated by minimizing the total energies with respect to atomic displacements. The energies are obtained by using the tight-binding scheme within the moments and continued-fraction formulation. The sign of the atomic displacements (inward or outward) of both the nearest and next-nearest neighbors varies with the size of the void. In addition, the displacements exhibit oscillations as a function of void size and do not appear to converge to atomic relaxations characteristic on surfaces even for the largest void studied. The relaxation of the first-nearest neighbor has a significant effect on the lifetime of positrons trapped in monovacancies, bringing theory to much better agreement with experiment. This effect, however, diminishes and becomes insignificant as voids grow in size.
Original languageEnglish
Pages (from-to)6-11
Number of pages6
JournalPhysical Review B
Volume37
Issue number1
DOIs
Publication statusPublished - 1 Jan 1988
MoE publication typeA1 Journal article-refereed

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