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DS: Fachverband Dünne Schichten

DS 26: Poster II

DS 26.29: Poster

Mittwoch, 25. März 2009, 09:30–12:30, P5

Time dependency of electric transport in epitaxial PCMO thin films — •Björn-Uwe Meyer, Peter Moschkau, Malte Scherff, Jörg Hoffmann, and Christian Jooss — Georg-August-Universität Göttingen, Göttingen, Germany

The great diversity of electrical properties in perovskite manganites vary from insulating to metallic behaviour. Depending on doping, temperature, magnetic- and electric field the insulating manganite Pr_1−xCa_xMnO₃ (PCMO) shows colossal resistance effects like CMR and CER. Furthermore PCMO reveals the electric pulse induced resistance (EPIR) change effect at room temperature. These pronounced resistance changes are acompanied by structural transitions i.e. polaronic order-disorder transitions. The relevant timescales of these changes are observable by the transient behaviour of the electrical conductivity and range from 20ns to several minutes, whereas long timescales are typical for low temperature switching. By means of pulsed voltage biases we investigated the time dependence of conductivity at different temperatures and applied external magnetic fields. The patterned PCMO thin films were prepared on MgO and STO substrates by ion beam sputtering and pulsed laser deposition. In addition, the samples were characterized by X-ray diffraction and, with respect to electronic phase seperation, by TEM.