Enhanced ferromagnetism in Mn-doped TiO2 films during the structural phase transition

The crystal structures and magnetic properties of Ti0.9747Mn0.0253O2 films prepared by sol–gel dip coating have been investigated. Room temperature ferromagnetism was observed both in the films of pure anatase phase and of mixed anatase and rutile phases. For the first time, enhancement of the ferromagnetism was revealed as the phase transition from anatase to rutile occurs: from 0.7±0.01μB/Mn to 1.1±0.05μB/Mn. The possible mechanism for the observed magnetism enhancement is discussed.