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MM: Fachverband Metall- und Materialphysik
MM 18: Poster Session
MM 18.20: Poster
Monday, March 31, 2014, 18:00–20:00, P4
Temperature dependence of the elastic constants of W: An ab-initio study — •Thomas Dengg1,2, Jürgen Spitaler1, Lorenz Romaner1, and Peter Puschnig2 — 1Materials Center Leoben Forschung GmbH — 2Karl-Franzens-Universität Graz, Institut für Physik
Two different ab-initio approaches for calculating the temperature dependence of the elastic constants of W are investigated. On the one hand the influence of temperature is taken into account only through the volume expansion. Here, thermal expansion can either be taken from experiment or determined theoretically within the quasiharmonic approximation. On the other hand the temperature dependence can explicitly be determined by calculating the free energy as a function of strain. To this end, the phonon density of states is calculated for a set of strained structures. The results from both approaches are compared with each other and it is assessed how they perform in terms of computational effort and accuracy and last but not least how well they agree with experimental values.