Room temperature magneto-optics of nanostructured ZnO:Mn thin film grown by spray pyrolysis

Undoped ZnO and ZnO:Mn thin films with different amounts of Mn concentration (5, 10 and 15 mol%) were grown on glass substrates by spray pyrolysis technique. X-ray diffraction patterns showed that the undoped ZnO thin film exhibited wurtzite structure preferably oriented in c-axis direction and the doped samples were polycrystalline. The surface morphology and topography of the films were investigated by SEM and STM micrographs. Magneto-optical characterizations of the samples were carried out by using Kerr and Faraday effects spectroscopy. Kerr effect studies showed that all Mn doped thin films exhibited the room temperature ferromagnetism. The magnetic ordering observed in the film with 5 mol% Mn concentration was stronger comparing to the other doped samples. The carrier densities of the samples were calculated by using a method based on the Faraday rotation. A clear relation between sp-d coupling and strength of magnetic ordering with carrier density was observed.