AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Thursday Sessions
       Session MI-ThM

Paper MI-ThM11
Effects of Heat Treatment on the Magnetic Properties of Nickel Cobalt Oxide Films

Thursday, November 18, 2004, 11:40 am, Room 304A

Session: Magnetic Oxides and Half-Metallics
Presenter: R.R. Owings, Pacific Northwest National Laboratory
Authors: R.R. Owings, Pacific Northwest National Laboratory
G.J. Exarhos, Pacific Northwest National Laboratory
T.C. Droubay, Pacific Northwest National Laboratory
C.F. Windisch, Pacific Northwest National Laboratory
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Spinel films of reactively sputtered nickel cobalt oxide exhibit an increase in saturation magnetization, up to ~5x, when rapidly quenched following heat treatment at 375° C for 10 minutes in air. The films appear to be weakly ferromagnetic with an in-plane saturation occurring in a field greater than 2000 G. Heat treatment followed by rapid quenching has also been shown to increase conductivity. Although the exact mechanism that relates the conductivity to the saturation magnetization is not well understood, the results of this work suggest that there is a relationship between the carrier movement and the spin orientation of the occupied orbitals in the octahedral or tetrahedral lattice positions. The effects of the heat treatment and cooling rate on the magnetic moment, electrical conductivity, index of refraction, IR transmission, and cation disorder are also discussed.