Regensburg 2007 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 10: Layers with Magnetic Properties
DS 10.7: Vortrag
Montag, 26. März 2007, 18:45–19:00, H34
LCMO Films Deposited on (100) and (111) STO Substrates — •Gulgun Hamide Aydogdu1, Yener Kuru2, and Hanns Ulrich Habermeier1 — 1Max Planck Institut für Festkörperforschung Heisenbergstraße 1, D-70569 Stuttgart, Germany — 2Max Planck Institut für Metallforschung Heisenbergstraße 3, D-70569 Stuttgart, Germany
Epitaxial LCMO thin films of various thicknesses were grown on (100) and (111) STO substrates by pulse laser deposition technique (PLD). Determination of epitaxial relationship between the film and the substrate, phase analysis were carried out by X-ray diffraction (XRD). It is understood by pole figures that films on (111) STO display three-fold symmetry however, four-fold symmetry is observed for the ones on (100) STO. Surface morphologies and roughnesses of the films were characterized by atomic force microscopy (AFM). Electrical resistivities and magnetization of the samples were measured within a temperature range between 5 K and 300 K. Films on (100) STO were found to behave as an insulator for all thicknesses while the films on (111) STO show metallic behavior when film thickness exceeds 145 nm. Structural variations induced by the (111) STO substrate cause the increase of the Mn-O-Mn angle and the equatorial Mn-O distances. Consequently, double exchange mechanism is enhanced and the Jahn-Teller distortion is decreased. This study is an example that shows how the substrate material can be used to modify the electronic and magnetic properties of the LCMO films although chemical compositions and the thicknesses of films remain unchanged.