A study of room-temperature ferromagnetism in transition metal and fluorine-doped spray-pyrolyzed SnO2 thin films

Room-temperature ferromagnetism has been observed in Co- or Mn-doped SnO 2 and Co- and F-co-doped SnO 2 thin films. A maximum magnetic moment of 0.80 μ B /Co ion has been observed for Sn 0.90 Co 0.10 O 1.925− δ F 0.075 thin films, whereas in the case of Sn 1− x Mn x O 2− δ it was 0.18 μ B /Mn ion for x =0.10. The magnetization of both Sn 1− x Co x O 2− δ and Sn 1− x Co x O 2− y − δ F y thin films depends on the free carrier concentration. An anomalous Hall effect has been observed in the case of Co-doped SnO 2 films. However, the same was not observed in the case of Mn-doped SnO 2 thin films. Carrier-mediated interaction is convincingly proved to be the cause of ferromagnetism in the case of Co:SnO 2 . It is, however, proposed that no carrier-mediated interaction exists in the case of Mn:SnO 2 . Present studies indicate that dopants and hence electronic cloud–lattice interaction plays an important role in inducing ferromagnetism.