Comparative studies on Zn0.95Co0.05O thin films on C-and R-sapphire substrates

Abstract

Zn0.95Co0.05O precipitate-free single crystal thin films were synthesized by a dual beam pulsed laser deposition method. The films form a wurtzite structure whose hexagonal axis is perpendicular or parallel to the plane of the surface depending on the C-plane (0001) or R-plane (110) sapphire substrate. Based on the results of high-resolution transmission electron microscopy and X-ray diffraction, C-plane films show larger lattice mismatch. The films exhibit magnetic and semiconductor properties at room temperature. The coercivity of the film is about 8000 A/m at room temperature. They are soft magnetic materials with small remanent squareness S for both crystal orientations. There is no evidence to show that the anisotropy is fixed to the hexagonal axis (C-axis) for the wurtzite structure. © 2009 Chin. Phys. Soc. and IOP Publishing Ltd.