Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 92: Postersession DS/HL

HL 92.5: Poster

Donnerstag, 10. März 2016, 16:00–19:00, Poster A

Spectroscopic Ellipsometry and MOKE as a Probe for Structural Properties of Spinel Oxide Thin Films — •Vitaly Zviagin¹, Peter Richter², Yogesh Kumar¹, Israel Lorite¹, Michael Lorenz¹, Daniel Spemann¹, Jan Meijer¹, Dietrich R.T. Zahn², Georgeta Salvan², Pablo Esquinazi¹, Marius Grundmann¹, and Rüdiger Schmidt-Grund¹ — ¹Universtät Leipzig, Institut für Experimentelle Physik II, Linnéstr. 5, Germany — ²Technische Universtät Chemnitz, Semiconductor Physics, Reichenheiner Str. 70, Germany

Normal, disordered, and inverse spinel oxide ferrite and cobaltite thin films were grown at different temperatures on MgO (100), MgAl₂O₄ (100), and SrTiO₃ (100) substrates by pulsed laser deposition. Assigned electronic transitions visible in diagonal and off-diagonal elements of the dielectric tensor show a clear dependence on growth temperature corresponding to the crystal quality of the films. Silicon irradiation of ZnFe₂O₄ films caused inversion of normal spinel structure as well as lattice distortion with further treatment, clearly visible in the dielectric function. The Zn_xFe_3−xO₄ composition was found to contain defects such as presence of Fe²⁺ ions. Magneto-optical Kerr effect spectroscopy was employed to investigate magneto-optically active transitions, and in combination with spectroscopic ellipsometry we obtained detailed information of site occupancy related to crystal inversion and disorder. We relate optical properties to magnetic properties to show a direct correlation between site occupancy of tetrahedral sites by Fe³⁺ ions to saturation and remanence magnetization.