Berlin 2008 – scientific programme

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MA: Fachverband Magnetismus

MA 32: Postersession II: Spinstruct./Phase Trans. (1-10); Spinelectronics (11-15); Thin Films (16 - 36); Particles/Clusters (37-45); Multiferroics (46-54); Spindynamics/Spin Torque (55 - 76); Post Deadlines (77-79)

MA 32.23: Poster

Friday, February 29, 2008, 11:15–14:00, Poster E

Growth and Characterization of La_1−xCa_xMnO₃ thin films with different Ca concentrations using PLD with in-situ RHEED — •Alexander Hirsch, Heiko Fasold, Ralf Koppert, Frank Ludwig, and Meinhard Schilling — TU Braunschweig, Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik, Hans-Sommer-Straße 66, D-38106 Braunschweig, Germany

The growth of doped perovskite manganites is interesting for both basic research and potential applications. These materials, which show the colossal magnetoresistance effect, have promise for new sensor applications, in particular as layers in multiferroic superlattices.

Using pulsed laser deposition (PLD), La_1−xCa_xMnO₃ (LCMO) thin films were grown. All targets were prepared by standard ceramic synthesis. As substrates SrTiO₃ (100) and NdGaO₃ (110) are used. The surface of the SrTiO₃ substrates is atomically flat and TiO₂ terminated after chemical and subsequent annealing treatment. To obtain atomically flat and single terminated NdGaO₃ surfaces an annealing treatment is applied. The growth of the films is monitored by in-situ reflection high energy electron diffraction (RHEED). The characterization is supplemented by X-ray diffraction and atomic force microscopy.

The LCMO films were grown with five different Ca concentrations between 33 % and 50 %. Optimal growth conditions lead to high quality crystalline magnetic films with rms roughnesses below 1nm for layer thicknesses up to 500 nm. The influence of the Ca concentration, the substrate and the film thickness on the properties of the thin films is analyzed.