Structural and magnetic properties of Co/Al2O3 cermet synthesized by mechanical ball milling

Abstract

Cobalt nanoparticles in the alumina matrix were synthesized using high energy mechanical ball milling of Co3O4 and Al powders mixture. The effect of ball mill time of 1 up to 12 h on the phase formation and crystalline lattice of the samples was investigated by the fitting of the X-ray diffraction patterns with Fullprof software and Rietveld method. The results show that 6 h milling of the primary powders yields a nanocomposite of Co/Al2O3 cermet. The formation of Co/Al2O3 nanocomposite was confirmed by a morphological study using scanning electron microscopy and transmission electron microscopy. The prepared nanocomposite by 12 h ball mill time has ferromagnetic properties with a high saturation magnetization value of 118 emu/g. Also, using Henkel plot analysis, it was shown that there are strong dipole-dipole magnetic interactions between the prepared cobalt nanoparticles in the Al2O3 matrix.