Berlin 2008 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 23: Poster session

MM 23.7: Poster

Dienstag, 26. Februar 2008, 14:45–18:00, Poster B

Investigation of Electronic Transport Mechanisms in Phase Change Materials — •Jennifer Luckas, Martin Salinga, Carl Schlockermann, Andreas Kaldenbach, Ursula Nellen, and Matthias Wuttig — I. Institute of Physics (IA), RWTH Aachen University, 52056 Aachen, Germany

The non-linearity of the electrical conductivity in the amorphous phase not only states to be the oldest of all puzzles in the field of phase change materials starting with Ovshinsky's discoveries in the 1960s, but also remains likely to be the most controversial one to this date. The most prominent effect in this context is the so-called threshold switching in the amorphous phase describing a sudden break down of resistivity in the presence of a critical electric field. Besides its scientific importance this effect is crucial for the currently most promising application of phase change alloys, i.e. electric memory (PCRAM).

Several theories about electronic transport of this class of materials have been proposed in the last decades, but there is still a lack of quantitative experimental data to validate or disprove them. To fill this gap in this work the mobility of the charge carriers is studied for some representative phase change materials. The dependence of the mobility both on temperature and on the electric field is investigated and compared with existing theories. From this comparison insight into the mechanism of charge carrier transport is obtained.