title: Ferromagnetism induced by clustered Co in Co-doped anatase TiO2 thin films.
abstract: We investigated ferromagnetism of a newly discovered ferromagnetic semiconductor Co-doped anatase TiO2 thin film, using the magnetic circular dichroism (MCD) at the Co L(2,3) absorption edges. The magnetic moment was observed to be approximately 0.1 micro(B)/Co in the measurements, but the MCD spectral line shape is nearly identical to that of Co metal, showing that the ferromagnetism is induced by a small amount of clustered Co. With thermal treatments at approximately 400 degrees C, the MCD signal increases, and the moment reaches up to approximately 1.55 micro(B)/Co, which is approximately 90% of the moment in Co metal. In the latter case, the cluster size was observed to be 20-60 nm.
authors.affiliation: Department of Physics & Electron Spin Science Center, Pohang University of Science and Technology, Pohang, Korea.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Kim
authors.forename: J-H
authors.initials: JH
authors.lastname: Park
authors.forename: B-G
authors.initials: BG
authors.lastname: Park
authors.forename: H-J
authors.initials: HJ
authors.lastname: Noh
authors.forename: S-J
authors.initials: SJ
authors.lastname: Oh
authors.forename: J S
authors.initials: JS
authors.lastname: Yang
authors.forename: D-H
authors.initials: DH
authors.lastname: Kim
authors.forename: S D
authors.initials: SD
authors.lastname: Bu
authors.forename: T-W
authors.initials: TW
authors.lastname: Noh
authors.forename: H-J
authors.initials: HJ
authors.lastname: Lin
authors.forename: H-H
authors.initials: HH
authors.lastname: Hsieh
authors.forename: C T
authors.initials: CT
authors.lastname: Chen