Structural and magnetic evolution of Fe-doped TiO2 nanoparticles synthesized by sol-gel method

Nanocrystalline Ti1-x Fe x O2 particles were fabricated via sol-gel method and their structures, morphology and magnetic properties were investigated. The structure of the Ti1-x Fe x O2 nanospheres evolved from mixed anatase and rutile phases to pure anatase phase with increasing iron content. Additionally, it is found the evolution of magnetism: sample x = 3% shows room temperature ferromagnetism while the rests exhibit paramagnetism. The hysteresis loop of sample x = 3% is attributable to paramagnetic and ferromagnetic phase and the paramagnetic and ferromagnetic components are separated. The susceptibility of Ti1-x Fe x O2 increases and then decreases with the increase of Fe content. The magnetism is explained by the BMP theory.