Luminescent and Magnetic Properties of Fe3O4@SiO2@Y2O3:Eu3+ Composites with Core-Shell Structure

Multifunctional Fe3O4@SiO2@Y2O3:Eu3+ composites were prepared with a facile solvothermal method followed by a subsequent heat treatment. Their structure and magnetic and luminescent properties were analyzed and discussed. Y2O3:Eu3+ phosphor as a shell was coated on the surface of Fe3O4@SiO2 as the core to form Fe3O4@SiO2@Y2O3:Eu3+ composites. The particle size of the composites is 262.36 nm which consists of the magnetic core with about 210 nm in diameter and a silica shell with an average thickness of about 20 nm. It exhibits ferromagnetic behavior with the special saturation magnetization M-s of 12.62 emu/g, the negligible coercivity H-c, and remanence M-r at room temperature and exhibits a strong red emission peak originating from the electric-dipole transition D-5(0) -> F-7(2) of Eu3+ ions at 611 nm. The current and potential biomedical uses include biological imaging, cell tracking, and magnetic bioseparation.