Positron Lifetimes in Solids from First Principles Calculations

Abstract

This is a preprint of a paper intended for publication in a journal or proceedings. Since changes ,_aay be made before publication, this preprint is made availab!e with the understanding that it will not be cited or reproduced without the perm/ssion of the author.] MASTER ABSTRACTWe present a first principles method for calculating positron lifetimes in solids, based on selfconsistent calculations using the Linear Muffin-Tin Orbital method. Local density approximations are used for both electron-electron and electron-positron interactions. Results are presented for a variety of elemental metals and vacancies to demonstrate the reliability of this approach. Theoretical calculations of positron lifetimes can be used to interpret experimental data. As an example of this, we interpret our experimental lifetime data for the oxide superconductor Ba__:K_BiO3 using calculations based on this method.