Palmitic acid-coated magnetite nanocubes with high-quality crystallinity and bulk-like magnetic features

We have demonstrated the synthesis of high-quality monocrystalline magnetite nanocubes through the introduction of palmitic acid as surfactant in a thermal decomposition synthesis of an organic Fe precursor. Unlike the standard thermal decomposition synthesis route, we report the avoid of the reducing agent and a modification in the synthesis heating ramp. Structural and magnetic properties were investigated showing well defined cubic shaped nanoparticles with a ∼ 40 nm edge and magnetic features close to bulk magnetite. We associate the bulk-like magnetic performance and properties to the highly crystalline structure of the nanocubes. In addition, we introduce a facile way to make a ligand exchange of nanocubes initial surfactant to citric acid in order to obtain biocompatible hydrophilic nanocubes. The potential application of the obtained sample in magnetic hyperthermia therapy is shown through calorimetric heating measurements on liquid dispersions of the nanocubes. We compute the Specific Absorption Rate to quantify the heating efficiency of the nanocubes.