Effect of the deposition parameters on the structural and magnetic properties of pulsed laser ablated NiO thin films

NiO thin films have been deposited on Si substrates using pulsed laser deposition technique. The effect of various experimental parameters, including the number of pulses, laser energy and frequency, oxygen pressure and substrate temperature, on the structure and morphology of NiO thin film has been studied. GIXRD results confirm the polycrystalline nature of the prepared thin films at all deposition conditions, but the preferred orientation of the film varies with the deposition conditions. The crystallite size in the prepared films is in the range of 4-33 nm. Morphology of the deposited films is orientation dependent. Magnetic behavior is correlated with the crystallite size of NiO films. Films with smaller particle size in the range of 4 to 6 nm display superparamagnetic behavior whereas large particle size films exhibit antiferromagnetic behavior. Optimized parameters for the deposition of smooth antiferromagnetic NiO pinning layer (for spin valve applications) are 10 Pa oxygen pressure, 2 mJ/mm(2) laser energy and 5 Hz laser frequency. (C) 2012 Elsevier B.V. All rights reserved.