Synthesis and Characterisation of Pure Cobalt Magnetic Nanoparticle by Metal Reduction

摘要

The study of nanoparticles magnet domains is of both fundamental and pressing technical interest as the magnetic properties depend strongly on grain size. Comparing magnetic properties of pure metal nanoparticles with different grain sizes will visualise the steps needed to form monodispersed magnetic nanoparticles. In this paper, the synthesis of Cobalt (Co) nanoparticles by metal salts reduction using cobalt chloride was studied. In addition, different stirring rate were applied while the syntheses were executed since it is believe that different rpm (revolution per minute) produce different impact to the particles growth. In order to control the particles size, combination of trialkylphosphine and oleic acid were used to produce tight ligands shell and allow particles to grow steadily. Samples of Co nanoparticles lesser than 15 nm has been prepared and discussed. From the analyses of transmission electron microscopy (TEM), the resultant particles were characterised to be highly crystalline. It was observed that the mean diameter decreased with increasing of the stirring rate.