Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 39: Computational Materials Modelling - Transport, Excitations, Time Dependence I

MM 39.5: Vortrag

Mittwoch, 13. März 2013, 16:00–16:15, H24

Embedded impurity method applied to positron annihilation lifetime simulations — •Martin Offenberger¹, John Banhart², and Hubert Ebert¹ — ¹Ludwig-Maximilians-Universität München — ²Helmholtz-Zentrum Berlin für Materialien und Energie

Within the Korringa-Kohn-Rostoker (KKR) framework of solid state simulations, the embedded impurity method is an efficient alternative to the supercell ansatz to describe impurity systems like substituted atoms or vacancies. This approach allows to study electronic properties and interactions between different alloying elements and vacancies on an atomic level.

As positrons are strongly attracted to vacancies and to a lesser degree to certain types of impurities, this method is of great advantage for positron annihilation studies.

We demonstrate the implementation of structural relaxation around impurities into the Munich SPRKKR band structure program package. Corresponding results for positron annihilation lifetimes of impurity-vacancy cluster systems embedded into Aluminium will be presented.

In addition the potential models (ASA or full potential) used within KKR calculations and their influence on electron and positron calculations for embedded impurity systems will be discussed.