Dresden 2011 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 44: Magnetic Half-metals and Oxides I

MA 44.8: Vortrag

Mittwoch, 16. März 2011, 18:45–19:00, HSZ 401

Resistive switching on La_0.8Ca_0.2MnO₃ films: nanoscale and time evolution studies of conductively switched domains — •Jon-Olaf Krisponeit, Christin Kalkert, Bernd Damaschke, Vasily Moshnyaga, and Konrad Samwer — I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen

The resistance behavior of perovskite manganites comprises a variety of interesting phenomena, reflecting the complexity of their microscopic constituents and the strong correlations among them. In addition to the temperature- and magnetic-field-induced metal-insulator transition (colossal magnetoresistance), manganites also exhibit a resistance switching driven by electric fields.

We have performed scanning force microscopy measurements (AFM) with conductively coated probes on a La_0.8Ca_0.2MnO₃ thin film and observed a bipolar switching behavior with a sharp threshold voltage. Current maps reveal nanoscale conducting domains which evolve in time and space under applied electric field.

We present a phenomenological model to describe the effect in terms of a local structural transition. An analysis of the growth behavior of the metallic regions during the voltage pulse further supports this scenario.

Acknowledgement: The work is supported by DFG via SFB 602, TP A2 and the Leibniz program.