Numerical modeling of impurities incorporated into vacancy clusters in graphene on copper, iron, tungsten substrate as studied by positron annihilation
Seminar “Theory of Condensed Matter”
Date and Time: Tuesday, 30 June 2020, at 4:00 PM
Venue: Online conference in Zoom, Bogoliubov Laboratory of Theoretical Physics
Seminar topic: «Numerical modeling of impurities incorporated into vacancy clusters in graphene on copper, iron, tungsten substrate as studied by positron annihilation»
Authors: A. A. Donkov (BLTP), E. Popov, A. Olejniczak, M. N. Mirzayev, K. Siemek, P. Horodek
Speaker: A. A. Donkov
The positron annihilation spectroscopy is a useful probe to detect the presence of defects in materials. Numerically one can obtain parameters useful for experimental comparison, such as the positron lifetime and the electron momentum distributions. In this presentation we show the results of such calculations to study the defects created by irradiation with protons and α particles in graphene on a substrate, and also consider some results obtained for irradiated SiC. As a conclusion, the obtained positron lifetimes correlate with the electron density at the defects, and we also see some limitations in the used code in treating Si vacancies in SiC.