Extended LaMer Synthesis of Cobalt-Doped Ferrite

Abstract

Nonstoichiometric cobalt ferrite nanoparticles have drawn interest in magnetically mediated energy delivery due to their high magnetocrystalline anisotropy and their high peak loss frequency. The use of an extended LaMer synthesis allows for size control of the doped particles up to a threshold core diameter of 18 nm. Above this diameter, particles become unstable and drop out of suspension, allowing for further nucleation events to occur. This leads to a cyclic nucleation, growth, and destabilization regime seen during the course of the reaction. Using the size control of the extended LaMer synthesis technique, we examine the specific absorption rate (SAR) as a function of particle size up to 18 nm and observe the same oscillatory behavior in the measured SAR values.