Synthesis and Magnetic Properties of Multifunctional Fe$_{3}$O$_{4}$-AuPt Core-Shell Nanoparticles

This paper describes the synthesis and magnetic properties of multifunctional Fe3O4-AuPt core-shell nanoparticles. The Fe3O4-AuPt core-shell nanoparticles were synthesized by a one-pot polyol process in two consecutive steps from Fe, Au, and Pt precursors. The structural characterization and property analysis proves the formation of the core-shell nanostructure fusing the multifunctionality in a single entity. The TEM observation shows that the Fe3O4-AuPt core-shell nanoparticles are highly crystalline and uniform in size distribution, with an averaged particle size of ~12.5 nm in diameter, whereas the X-ray diffraction patterns provide further substantiation. The surface plasmon resonance arising from the AuPt nano-shell was revealed by UV-vis spectroscopy, while the magnetic measurements by VSM and PPMS demonstrate the well-defined superparamagnetic and/or soft-ferromagnetic behavior of the Fe3O4-AuPt core-shell nanoparticles.