title: Above room temperature ferromagnetism in Si:Mn and TiO(2-delta)Co.
abstract: We present recent experimental results on the structural, electrical, magnetic, and magneto-optical properties of Mn-implanted Si and Co-doped TiO(2-delta) magnetic oxides. Si wafers, both n- and p-type, with high and low resistivity, were used as the starting materials for implantation with Mn ions at the fluencies up to 5 x 10(16) cm(-2). The saturation magnetization was found to show the lack of any regular dependence on the Si conductivity type, type of impurity and the short post-implantation annealing. According to XMCD Mn impurity in Si does not bear any appreciable magnetic moment at room temperature. The obtained results indicate that above room temperature ferromagnetism in Mn-implanted Si originates not from Mn impurity but rather from structural defects in Si. The TiO(2-delta):Co thin films were deposited on LaAlO3 (001) substrates by magnetron sputtering in the argon-oxygen atmosphere at oxygen partial pressure of 2 x 10(-6)-2 x 10(-4) Torr. The obtained transverse Kerr effect spectra at the visible and XMCD spectra indicate on intrinsic room temperature ferromagnetism in TiO(2-delta):Co thin films at low (< 1%) volume fraction of Co.
authors.affiliation: Faculty of Physics, Moscow State University, Vorob'evy Gory, 119991 Moscow, Russia.
authors.forename: A
authors.initials: A
authors.lastname: Granovsky
authors.forename: A
authors.initials: A
authors.lastname: Orlov
authors.forename: N
authors.initials: N
authors.lastname: Perov
authors.forename: E
authors.initials: E
authors.lastname: Gan'shina
authors.forename: A
authors.initials: A
authors.lastname: Semisalova
authors.forename: L
authors.initials: L
authors.lastname: Balagurov
authors.forename: I
authors.initials: I
authors.lastname: Kulemanov
authors.forename: A
authors.initials: A
authors.lastname: Sapelkin
authors.forename: A
authors.initials: A
authors.lastname: Rogalev
authors.forename: A
authors.initials: A
authors.lastname: Smekhova