First-principles calculation of positron lifetimes and affinities in perfect and imperfect transition-metal carbides and nitrides

Loading...
Thumbnail Image

Access rights

openAccess

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Authors

Puska, M. J.
Aob, M.
Brauer, G.
Korhonen, T.

Date

1994-04-15

Major/Subject

Mcode

Degree programme

Language

en

Pages

11
10947-10957

Series

Physical Review B, Volume 49, issue 16

Abstract

First-principles electronic structure and positron-state calculations for transition-metal carbides and nitrides are performed. Perfect NaCl structures as well as structures with metal or carbon/nitrogen vacancies are considered. The positron affinities and lifetimes are determined. The trends are discussed and the results are compared with recent positron lifetime measurements for group-IV and -V refractory metal carbides. The present analysis suggests, contradictory to an earlier interpretation, that positrons are trapped and annihilated at both carbon and metal vacancies. The concentration of metal vacancies detected by positron annihilation methods is probably very low, below the sensitivity limit of other experimental methods.

Description

Keywords

Other note

Citation

Puska , M J , Aob , M , Brauer , G & Korhonen , T 1994 , ' First-principles calculation of positron lifetimes and affinities in perfect and imperfect transition-metal carbides and nitrides ' , Physical Review B , vol. 49 , no. 16 , pp. 10947-10957 . https://doi.org/10.1103/PhysRevB.49.10947