N. Popovici

Magneto‐Optical Properties of Co‐doped TiO2 Thin Films Grown by Pulsed Laser Deposition

Co‐doped TiO2 thin films on (0001) Al2O3 were grown at 310°C by pulsed laser deposition, using a KrF excimer laser. The ablation of polycrystalline TiO2 rutile — Co3O4 targets was performed in a pure argon or mixed argon‐hydrogen atmosphere at total pressure of 10 Pa, with various H2 flow rates. X‐ray diffraction analysis showed that the as deposited films consist of TiO2 rutile‐based nanocrystallites with preferred orientation along the [101] direction. The chemical composition of the samples was evaluated by Rutherford backscattering measurements, revealing that Ti distribution is homogeneous on the surface and along film depth, and that the Co:Ti ratio is 0.03:0.97 for all the films investigated. In this paper, preliminary magnetic circular dichroism spectroscopy measurements on a 2.1μm film grown in a mixed argon/hydrogen atmosphere is suggestive of spin splitting at the band‐edge energy of our films.