Characterizations of FeCl/Cu superlattices sputtered at low and high deposition rates of ferromagnetic layer

Abstract

FeCl/Cu superlattices was grown using a dc magnetron sputtering at low (0.02 nm/s) and high (0.08 nm/s) deposition rates of ferromagnetic layer, and the properties of the superlattices were investigated. Structural characterizations by x-ray diffraction (XRD) technique showed that a mixture of the face centered cubic (111) and the body centered cubic (110) structure formed in the superlattices. In the XRD patterns, the peak intensity of (111) is higher for the superlattices grown at low deposition rate whereas the (110) peak intensity is higher at high deposition rate, and hence the preferential orientation turned from (111) to (110) when the deposition rate of the FeCl layer was increased from 0.02 nm/s to 0.08 nm/s. Compositional analysis of the superlattices by energy dispersive x-ray spectroscopy revealed that the Fe and Cl contents were 7 at % and 66 at %, respectively while the Cu content of the superlattices was detected to be 27 at.%. The morphology was exposed with a scanning electron microscope. The superlattice surfaces were coherent and bright. The atomic force microscopy images showed that the surfaces have almost the same roughness. The magnetic measurements revealed that the saturation magnetization and the coercivity increased with increasing deposition rates from low to high deposition rate. Also the magnetic easy axis was found to be in the superlattice plane for all superlattices. It was seen that the variations in the magnetic properties of the superlattices might be attributed to the structural changes grown at low and high deposition rates of ferromagnetic layer.