Tuning the Properties of Iron Oxide Nanoparticles in Thermal Decomposition Synthesis: A Comparative Study of the Influence of Temperature, Ligand Length and Ligand Concentration

Abstract

Whilst the synthesis of magnetic nanoparticles via the non-aqueous thermal decomposition method has proven to lead to the most defined products, the tailoring of their properties is still largely achieved empirically, in particular for metal oxide nanoparticles. In this paper, the influence of ligands with varying length and concentration on the properties of the resulting magnetic nanoparticles is studied, and it is shown that the reaction temperature rather than the ligand length or concentration crucially influences the properties in various ways. The obtained particles are characterized with regard to their size, morphology, crystallinity, and magnetic characteristics, using techniques like transmission electron microscopy (TEM), X-ray diffraction (XRD), and superconducting quantum interference device (SQUID) magnetometry measurements. It is thereby shown that the optimum choice of ligand and synthesis conditions not only serves to ensure monodispersity of the resulting particles but also to realize high colloidal stability and redispersibility.