Dresden 2017 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 10: Computational Materials Modelling - Accelerated Approaches
MM 10.6: Vortrag
Montag, 20. März 2017, 13:00–13:15, IFW B
Ab initio determination of phonon lifetimes at elevated temperatures — •Albert Glensk1, Blazej Grabowski1, Tilmann Hickel1, Jörg Neugebauer1, Pascal Neibecker2, Jürgen Neuhaus2, Michael Leitner2, Klaudia Hradil2, and Winfried Petry2 — 1Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf, Germany — 2Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany
The experimental measurement of phonon dispersions is well established. The corresponding phonon lifetimes (i.e., inverse linewidths) are - in contrast - assessed experimentally only for a handful of materials and are usually restricted to room temperature where anharmonic effects are small. Standard theoretical methods applying perturbation theory have shown to successfully describe the underlying phonon-phonon interactions at low temperatures. However, significant discrepancies to experiment (~100%) are found at elevated temperatures where the phonon broadening due to anharmonicity becomes large [1-2]. Applying the recently developed Local Anharmonic approximation [3] we determine ab initio values for phonon lifetimes in Al for a temperature range up to melting. We discuss its performance in comparison to previous perturbative approaches and our own experimental assessments for this temperature range.
[1] J. Pang et al., PRL 110, 157401 (2013).
[2] X. Tang et al., PRB 84, 054303 (2011).
[3] A.Glensk et al., PRL 114, 195901 (2015).