Regensburg 2002 – wissenschaftliches Programm

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MA: Magnetismus

MA 19: Spinstrukturen und magnetische Phasenübergänge (incl. Sensoren(19.11) und Messmethoden(19.12-13))

MA 19.8: Vortrag

Donnerstag, 14. März 2002, 17:00–17:15, H23

STM studies on perovskite manganite samples — •Pintu Das, Y. Xu, M.R. Koblischka, and U. Hartmann — Institute of Experimental Physics, University of Saarbr"ucken, P. O. Box 151150, 66041 Saarbr"ucken

Scanning Tunneling Microscopy (STM) is an important tool to obtain information on the electronic properties of conducting materials. Here we report the results of topography and spectroscopy measurements on thin films of La_0.67A_0.33MnO₃ (A = Sr, Ba) and a bulk, polycrystalline sample of La_0.67Ca_0.33MnO₃ by means of an STM. The samples have the ferromagnetic to paramagnetic transition tempratures (T_c) at 368 K, 345 K and 275 K, respectively. The measurements are carried out at room temperature, i.e. below or close to their Curie temperatures. A comparative study of the density of states (DOS) near the Fermi energy (E_f) of these colossal magnetoresistance (CMR) materials is also made at room temperature.