Berlin 2008 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 20: Multiferroics

MA 20.15: Vortrag

Mittwoch, 27. Februar 2008, 17:45–18:00, EB 202

Growth and Characterization of La_0.67Ca_0.33MnO₃ and BaTiO₃ multilayers using PLD with in-situ RHEED — •Alexander Hirsch, Heiko Fasold, Ralf Koppert, Christian Wille, Frank Ludwig, and Meinhard Schilling — TU Braunschweig, Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik,

One way to design multiferroics, i.e., materials with ferroelectric and ferromagnetic properties, for new sensor applications is to grow superlattices with alternating ferromagnetic and ferroelectric layers.

Using pulsed laser deposition (PLD) La_0.67Ca_0.33MnO₃ (LCMO) and BaTiO₃ (BTO) multilayers are grown on SrTiO₃ (100) substrates. To obtain atomically flat and single terminated substrate surfaces a chemical and subsequent annealing treatment is applied. All targets were prepared by standard ceramic synthesis. The growth of the films is monitored by in-situ reflection high energy electron diffraction (RHEED), which is a powerful tool for optimizing thin films with the objective of superlattice growth. In addition, the thin films are characterized by X-ray diffraction and atomic force microscopy.

Superlattices with alternating LCMO and BTO layers are grown, with BTO layer thicknesses ranging from 4 u.c. to 16 u.c. and LCMO layer thicknesses of 5 u.c.. RHEED intensity oscillations are used to control the thickness of the multilayers. Superlattices up to thicknesses of approx. 825 nm were grown. The influence of the BTO layer and the superlattice thickness, respectively, on the properties is analyzed.