Influence of Mn doping on structural and magnetic properties of Ti_(1-x)Mn_xO_2

摘要

We report here the structural and magnetic properties of Mn-doped TiO_2 samples (0 ≤ Mn ≤ 0.06) prepared with a solid-state method. The cell parameters a and c increased with the increased Mn content, implying that Mn ions were substituted into the lattice of TiO_2. The room-temperature M(H) loops showed ferromagnetism (FM) behavior for all samples. The magnetic moment per Mn atom decreased with the increased Mn content. However, our results demonstrate that the FM property is intrinsic to the TiO_2 system and is not a result of any secondary magnetic phase or cluster formation. The magnetic properties of Ti_(1-x)Mn_xO_2 are discussed based on the competition between the antiferromagnetic superexchange coupling and the FM originating from interactions between Mn ions and oxygen vacancies and/or defects inserted in the TiO_2 lattice.