Magnetization Study of CoxCu1-x Nanoparticles

Nanostructured CoCu granular alloys have been prepared by chemical reduction method using NaBH4 as a reducing agent and characterized by inductively coupled plasma optical emission spectroscopy (ICPOES), x-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. Zero-field cooled and field cooled (ZFC/FC) magnetization study shows a blocking temperature distribution resulting from particle size distribution which is a characteristic of superparamagnetism. Magnetization study reveals that at low Co concentration, the alloy particles are superparamagnetic. At higher Co concentration the magnetization is combination of ferromagnetism (FM) and superparamagnetism (SPM). The coercive field is independent of Co concentration.