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TT: Fachverband Tiefe Temperaturen

TT 44: Poster Session Correlated Electrons

TT 44.44: Poster

Thursday, March 17, 2011, 10:00–13:00, P1

Temperature-dependent near-edge x-ray absorption fine structure of (La_1−yPr_y)_0.7Ca_0.3MnO₃ — •Stephan Uebe^1,2, Andrea Assmann^1,2, Michael Merz¹, Markus Wissinger^1,2, Hilbert von Löhneysen^1,3, Sebastian Hühn⁴, Vasily Moshnyaga⁴, Peter Nagel¹, and Stefan Schuppler¹ — ¹KIT, Institut für Festkörperphysik, Karlsruhe — ²KIT, Fakultät für Physik, Karlsruhe — ³KIT, Physikalisches Institut, Karlsruhe — ⁴Universität Göttingen, Physikalisches Institut, Göttingen

All members of the (La_1−yPr_y)_0.7Ca_0.3MnO₃ (LPCMO) doping series are strongly correlated electron systems where the electron-electron interaction gives rise to the macroscopic feature of colossal magnetoresistance (CMR). Changing the La/Pr ratio allows for tuning the electron-phonon coupling and thereby T_C.

Thin films of LPCMO were grown on MgO by the Metalorganic Aerosol Deposition technique. The temperature-dependent near-edge x-ray absorption fine structure of the samples was recorded with special emphasis on a double-peak structure that emerges when cooling below T_C.

This feature is known to be specific for CMR manganites and different scenarios have been suggested in literature to explain this change in the electronic structure, being obviously concomitant with the MI phase transition.

Based upon our experimental findings, we will discuss the various scenarios and their respective implications.