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MA: Fachverband Magnetismus

MA 45: Focus: Disorder Engineering as a Tool for Material Science

MA 45.4: Hauptvortrag

Donnerstag, 10. März 2016, 16:45–17:15, H32

The Impact of Disorder on Transport in crystalline Phase Change Materials — •Matthias Wuttig — RWTH Aachen

Understanding charge transport in phase change materials (PCM) is crucial to extend the application range of these exciting materials. Hence, we have studied the resistivity of crystalline phase change materials. A pronounced dependence of the room temperature resistivity upon annealing temperature is observed for crystalline PCMs such as Ge1Sb2Te4. This finding is corroborated by low temperature measurements as well as FTIR data, which confirm that a metal * insulator transition is observed without a change in crystallographic state. This is indicative for an electronically driven MIT [1].

Such an MIT can be achieved if the electron correlation exceeds a critical value (Mott MIT). A second route to insulating behavior has been attributed to increasing disorder, which turns a metal into an insulator with localized states. Arguments for disorder induced localization of charge carriers will be presented, which reveal that vacancy ordering drives the MIT [2]. The potential of disorder for applications as well as our fundamental understanding of solids is discussed. [1] T. Siegrist et al., Nature Materials 10, 202, (2011) [2] W. Zhang et al., Nature Materials, 11, 952 (2012).