Journal Article

IMPULSE-2026-00075

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Ab Initio Calculations of Positron Lifetimes in Diamond: The Bulk, Vacancies and Grain Boundary

Dickmann, M.MLZ* ; Helm, R.MLZ* ; Egger, W.MLZ* ; Mitteneder, J.MLZ* ; Duffek, J. A. ; Jarmatz, P. ; Dollinger, G.

2025
Trans Tech Publications Ltd. Baech

Please use a persistent id in citations: doi:10.4028/p-BcfuL0

Abstract: In this study, we present positron lifetime calculations for diamond, including the defect-free bulk, vacancies and vacancy clusters, as well as grain boundaries, using Two-Component Density Functional Theory. Our results show a positron bulk lifetime of 103 ps and a mono-vacancy lifetime of145 ps, which is in agreement with experimental data. We calculated positron lifetimes for vacancy clusters from 2 up to 40 missing atoms, resulting in lifetimes between 168 to 365 ps. From these results, we derived a function that correlates the cluster size with the respective positron lifetime.Furthermore, we computed the positron lifetime of 124 ps for a grain boundary, which is between the bulk and mono-vacancy lifetime. Our results will be used to interpret measured positron lifetime spectra in diamond.

Keyword(s): Chemical Reactions and Advanced Materials (1st) ; Condensed Matter Physics (2nd)

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Contributing Institute(s):

1. NEPOMUC (NEPOMUC)

Experiment(s):

1. No specific instrument

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Database coverage:
National-Konsortium ; SCOPUS

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