Published online by Cambridge University Press: 31 January 2011
Dilute magnetic semiconductors are ferromagnetic semiconductors recently discovered in nitride and oxide semiconductors by incorporating a small percentage of magnetic atoms into the semiconductors host. Recently it is reported that the structural and electrical properties of pure indium oxide can be modified by growth parameters. In this paper we investigate magneto-transport properties of Co-doped In2O3 dilute magnetic semiconductors thin films grown on sapphire and quartz substrates using pulsed laser deposition technique. The effect of partial oxygen pressure on structural, electrical, optical, and magneto-transport properties was discussed in details. The crystallinity of the films largely depends on growth temperature. Magneto-transport properties such as temperature dependent resistivity and magneto-resistance were found to be very sensitive to the micro-structural properties such as crystalinity as well as oxygen defect. The electrical carrier density of the films depends on oxygen pressure and a change of two orders of magnitude is observed. Depending on growth parameters, both positive and negative magneto-resistance is observed. Optical band-gap seems to vary with the growth partial oxygen pressure.