Dresden 2014 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 37: Preparation and characterization

HL 37.2: Talk

Tuesday, April 1, 2014, 09:45–10:00, POT 151

Optical Anisotropies in Magnetite (110) — •Karsten Fleischer¹, Ruggero Verre², Ozhet Mauit¹, John F. McGilp¹, and Igor V. Shvets¹ — ¹School of Physics, Trinity College Dublin, Ireland — ²Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden

Reflectance anisotropy spectroscopy (RAS) has been used to measure the optical anisotropies of bulk and thin film Fe₃O₄(110). The spectra resemble the derivative of the dielectric function of the samples, indicating that small shifts in energy of the optical transitions, such as those associated with anisotropic strain or electric field gradients, are responsible for the strong signal observed. The RAS response was then measured as a function of temperature. A distinct change in the RAS line shape amplitude was observed in the spectral range from 0.8 to 1.6 eV for temperatures below the metal-insulator Verwey transition of the crystal at T=110K. These changes are discussed in terms of charge ordering models in the crystal.