Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 25: Correlated Electrons - Poster Session

TT 25.89: Poster

Mittwoch, 29. März 2006, 14:30–18:30, P1

Electric-field-induced insulator-metal transition in thin films of Pr_0.68Ca_0.32MnO₃ — •Sebastian Schramm, Peter Moschkau, and Christian Jooss — Institut für Materialphysik, Universität Göttingen

Experimental analysis and understanding of electronic phase separation in hole-doped manganites offer a fascinating research area for the fundamental properties of correlated electrons in solids. That is why those manganites are of great interest and their behaviour in electric fields should be understood. In this work Pr_0.68Ca_0.32MnO₃(PCMO)-thin films prepared by Pulsed Laser Deposition on SrTiO₃-Substrates are examined concerning their electrical transport properties. In constant-current-measurements, a resistance collapse of several orders of magnitude is observed while cooling below 175K. The resistivity exhibits a huge temperature hysteresis, which depends on the electric history of the sample. In further research explicit indications will be sought whether this abnormal resistance behaviour is due to a homogeneous or inhomogeneous resistance change in the film. There are a number of experimental evidences in favour of the inhomogeneous model, where a metallic, possibly ferromagnatic filament emerges in an insulating paramagnetic matrix.