Electronic manifestation of cation-vacancy-induced magnetic moments in a transparent oxide semiconductor: Anatase Nb:TO2

Abstract

A study was conducted to demonstrate the magnetic effect in the Nb-doped anatase TiO2 functional material when grown under specific conditions using electrical characterization. One significant advantage of the electrical measurement of the magnetic effect was that it revealed key information about the coupling between the itinerant carriers and localized magnetic moments. The electrical results excluded any contribution from unintentional metallic contamination of the films during handling or from magnetic impurities in the substances. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) measurements provided clear evidence of the cation-vacancy origin of magnetism of the material. Specific cation valence states or other defect states were demonstrated to be the two potential origins of the local magnetic moments in the Nb-dopted TiO2 samples.