Room-temperature ferromagnetic properties in Mn-doped rutile TiO2-δTiO2-δ thin films

Room-temperature ferromagnetic properties of Mn-doped reduced titanium dioxide (Ti1-xMnxO2-δ)(Ti1-xMnxO2-δ) thin films with rutile structure synthesized by a sol–gel method have been detected for a limited range of Mn composition (x)(x). The Ti1-xMnxO2-δTi1-xMnxO2-δ films were found to be p-type semiconducting with hole concentration near 1019cm-3. The observed ferromagnetism in the Ti1-xMnxO2-δTi1-xMnxO2-δ films is not related to the hole concentration but related to x. The room-temperature ferromagnetism is attributable to magnetic polaron formed by trapped electron in oxygen vacancy and magnetic ions around it. Thus, the existence of oxygen vacancies is necessary for the room-temperature ferromagnetism.