Berlin 2024 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 24: Transport in Materials: Diffusion, Conduction of Charge or Heat II
MM 24.6: Vortrag
Dienstag, 19. März 2024, 13:00–13:15, C 264
Violation of Boltzmann quasi-particle transport in disordered alloy — •Gabor Csire1, Franco Moitzi1, Andrei Ruban1,2, and Oleg Peil1 — 1Materials Center Leoben Forschung GmbH, Roseggerstraße 12, 8700 Leoben, Austria — 2KTH Royal Institute of Technology, Brinellvagen 23, SE-100 44 Stockholm, Sweden
High resistivity disordered metals often exhibit deviations from the transport behavior described by the semiclassical Boltzmann theory. Here the scattering events from impurities or phonons cannot be treated as independent processes as suggested by Matthiessen's rule. The most extreme example of such a behavior are crystalline metallic alloys that exhibit a crossover from the positive to negative sign of the temperature coefficient of resistivity that persists from low to high temperatures. Various mechanisms, including weak localization and polaronic effects, have been put forward to explain the behavior within the framework of the Boltzmann transport theory but since most of these studies were relying on simple models a clear physical picture and quantitative material-specific description are still missing. In this contribution, we investigate the temperature-dependent resistivity of such ,,anomalous'' alloys using our recent implementation of the Kubo-Greenwood formalism within the Korringa-Kohn-Rostoker method using Andersen's muffin-tin-orbital representation. In particular, we examine the temperature evolution of the non-Boltzmann transport contributions and discuss the origin of the sign change in the temperature coefficient.
Keywords: disorderded systems; KKR-CPA method; transport