Synthesis and Characterization of Magnetic FePt/Au Core/Shell Nanoparticles

We report a two-step chemical solution process for synthesis of FePt/Au core/shell nanoparticles. First, FePt nanoparticles were synthesized using a typical polyol process. The as-synthesized FePt nanoparticles were then used as seed materials and were coated with gold shells by reduction of the gold precursors. The coated nanoparticles have been characterized using various structural and morphological measurements to confirm the FePt/Au core/shell morphology. The as-synthesized FePt/Au nantoparticles were found to be superparamagnetic and became ferromagnetic after annealing at 400 degrees C. The surface modification of FePt/Au core/shell nanoparticles from hydrophobic to hydrophilic was achieved through ligand exchange to make them water dispersible for potential biomedical applications.