Curie temperature of Co-doped TiO2 as functions of carrier density and Co content evaluated from electrical transport and magnetization at low temperature regime

Abstract

Curie temperature (TC) of anatase Co-doped TiO2 epitaxial thin films was systematically investigated as functions of carrier density (n) and Co content (x) by electrical transport and magnetization measurements at low temperature regime. The estimated TC from both measurements showed similar TC. For x = 0.03, 0.05, and 0.07, non-monotonic TC vs. N relations were observed, whereas TC was monotonically increasing function of n for x = 0.10. Possible mechanism of high TC ferromagnetism for this compound was discussed.