Reagent control over the composition of mixed metal oxide nanoparticles

Binary (M1 − M2 − O) and ternary (M1 − M2 − M3 − O) metal-oxide nanoparticles (NPs) have been prepared by thermal decomposition in benzyl ether of the appropriate M(acac)n (M = Fe, Mn, Pd, Cu, Al, Gd) compounds in the presence of a mixture of oleic acid and oleylamine templating (surface capping) ligands, and 1,2-hexadecanediol as an accelerating agent. The metal percentage and the particle size were investigated as a function of the starting composition. The NP composition is controlled by the relative reaction rates of the particular precursors, such that prediction of NP composition from reagent ratios is not straightforward. However, understanding reaction rate limitations allows for alternative synthesis to be developed. In some cases, ligand exchange reaction and subsequent decomposition are possibly more important than thermal decomposition.