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MM: Fachverband Metall- und Materialphysik

MM 43: Computational Materials Modelling - Transport, Excitations, Time Dependence II

MM 43.1: Vortrag

Mittwoch, 13. März 2013, 16:30–16:45, H24

On low-energy electronic excitations in the Ti_1−xAl_xN-system — •Simon Lamowski, Torsten Weißbach, and Jens Kortus — TU Bergakademie Freiberg, Institut für Theoretische Physik, Leipziger Straße 23, 09599 Freiberg, Germany

Layered structures of Ti_1−xAl_xN were characterized by electron energy-loss spectroscopy scanned along a direction perpendicular to the interface. By means of ab initio Density Functional Theory (DFT) calculations using the full potential linearised augmented plane wave (FP-LAPW) method as implemented in the Elk code [1] we investigate structural and electronic factors which influence the EELS up to an energy-loss of 60 eV.

Further, we go beyond standard DFT by solving the Bethe-Salpeter-Equation [2] to obtain the free parameters for the long range contribution exchange - correlation kernel [3] for time dependent DFT (TDDFT). This allows to use the TDDFT with lower computational cost to calculate EELS for supercells with defects and layers.

[1] Dewhurst K, et al. Elk. Version: 1.4.22 Available from: http://elk.sourceforge.net/

[2] Salpeter EE, Bethe HA. Physical Review; 1951;84(6):1232.

[3] Botti S, et al. Physical Review B; 2005;72(12):125203.