Co-occurrence of superparamagnetism and anomalous hall effect in highly reduced cobalt-doped rutile TiO2-δ films

Superparamagnetizm in highly reduced cobalt (Co)-doped rutile TiO 2-δfilms displaying an anomalous Hall effect (AHE) was investigated. The presence of nanosized superparamagnetic cobalt clusters of ∼8-10 nm size in the films at the interface was established using the magnetization and transmission electron microscopy. In a single-domain particle the easy directions of magnetization were separated by the anisotropy barrier. The results indicate the co-occurrence of superparamagnetizm and AHE.