Anomalous Hall effect in anatase Ti 1 − x Co x O 2 − δ at low temperature regime

Anomalous Hall effect (AHE) of a ferromagnetic semiconductor anatase Ti 1 − x Co x O 2 − δ thin film is studied from 10 to 300 K . Magnetic field dependence of anomalous Hall resistance is coincident with that of magnetization, while the anomalous Hall resistance decreases at low temperature in spite of nearly temperature-independent magnetization. Anomalous Hall conductivity σ AHE is found to be proportional to the square of Hall mobility, suggesting that charge scattering strongly affects the AHE in this system. The anatase Ti 1 − x Co x O 2 − δ also follows a scaling relationship to conductivity σ x x as σ AHE ∝ σ x x 1.6 , which was observed for another polymorph rutile Ti 1 − x Co x O 2 − δ , suggesting an identical mechanism of their AHE.