Influence of the milling materials on the mechanochemical synthesis of magnetic iron oxide nanoparticles

Abstract

The aim of this work is to synthesize iron oxide nanoparticles (IONPs) by a mechanochemical process using a high-energy planetary ball mill, with two types of vials and balls (stainless-steel and zirconia) and two reactive mixtures. This preparative route is simple, scalable and environmentally friendly. The influence of milling materials on the structural and magnetic properties of the obtained IONPs was studied. Composition, crystalline structure, morphology and magnetic properties of the IONPs were analyzed by XRD, Raman spectroscopy, SEM, TEM and VSM techniques. An iron oxide with spinel structure, compatible with magnetite (Fe3O4) or maghemite (γ-Fe2O3), was formed in the prepared samples, when using FeCl3 or FeCl3/Fe with stainless steel vials, or FeCl3/Fe with zirconia vials. The results indicate that the formation of spinel magnetic phases is strongly influenced by the presence of metallic Fe in the starting mixture as well as the nature of the container, which can (or cannot) supply Fe during the milling. The obtained results are presented with a perspective oriented to the biomedical application of the IONPs, considering mean particle sizes, magnetic properties, and chemical stability in simulated body fluids.