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MA: Magnetismus

MA 23: Spinabh
ängiger Transport III

MA 23.10: Talk

Tuesday, March 8, 2005, 12:45–13:00, TU H1028

Transport properties of PCMO in magnetic and electrical fields — •Wilko Westhäuser und Christian Jooß — Institut für Materialphysik, Universität Göttingen

Pr_0,68Ca_0,32MnO₃ (PCMO) is very sensitive to certain external perturbations inducing a phase transition from a charge-ordered antiferromagnetic state to a charge-delocated ferromagnetic state. We investigate the electric field driven phase transition in comparison to the well-known colossal drop in resistance caused by an applied magnetic field (CMR) in several samples: poly-crystalline sintered pellets and epitaxial, laser-deposited thin films on single-crystalline SrTiO3- and MgO-substrates. In These samples we find significant differences in the metal-insulator (MI) transition which are due to strain and lattice defects. Evidences that the MI transition driven by electric fields is localized in a filamentary path are presented.