Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 40: Poster II: Bio- and Molecular Magnetism (1-9); Magnetic Coupling Phenomena/Exchange Bias (10-15); Magnetic Particlicles and Clusters (16-29); Micro and Nanostructured Magnetic Materials (30-51); Multiferroics (52-64); Spin Injection in Heterostructures (65-67); Spin-Dyn./Spin-Torque (68-93); Spindependent Transport (94-108)

MA 40.95: Poster

Freitag, 27. März 2009, 11:00–14:00, P1A

AC Transport in thin manganite films — •Sebastian Hühn, Kai Gehrke, Vasily Moshnyaga, and Konrad Samwer — I. Physikalisches Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37707 Göttingen

We have studied the metal-insulator (MI) transition in perovskite manganite films by means of a.c. electric transport technique. The films of La_1−xSr_xMnO₃ (LSMO), La_1−xCa_xMnO₃ (LCMO) and (La_1−yPr_y)_1−xCa_xMnO₃ (LPCMO) were prepared by a metalorganic aerosol deposition technique. The linear R_ω and nonlinear 3^rd harmonic resistance R_3ω were measured simultaneously as a function of temperature (4-300K), current (1-1000µA), frequency (1-1000Hz) and magnetic field (0-7T). We show that the MI transition temperature (T_MI) is frequency dependent. The nonlinear resistance R_3ω is strongly enhanced mostly in the vicinity of T_MI and shows a peculiar magnetic field dependance. The results on LPCMO film are compared with LCMO and LSMO and discussed within correlated polarons approach and phase separation scenario.

Deutsche Forschungsgemeinschaft via SFB 602, TPA2 is acknowledged