Multifunctional nanocomposites with different coupling agents: synthesis, luminescent and magnetic properties

In this study, the co-precipitation method has been developed for the synthesized Fe₃O₄ nanoparticles which are encapsulated with SiO₂/C/TiO₂ via the facile and further functionalized by the deposition of Y₂O₃:Eu³⁺ phosphors. Transmission electron microscopy images revealed that the nanocomposites show a spherical morphology with size distribution around 100–250 nm, and the thickness of the coupling agents was 3–4 nm. The X-ray diffraction patterns showed that a cubic spinel structure of Fe₃O₄ core and a tetragonal phase of Y₂O₃:Eu³⁺ shell was obtained. The multifunctional nanocomposites showed ferrimagnetic behavior, the negligible coercivity Hc and remanence Mr at room temperature and showed unique europium fluorescence properties with strong red emission peak from the electric–dipole transition ⁵D₀ → ⁷F₂ of Eu³⁺ ions at 611 nm. Therefore, the multifunctional nanocomposites are expected to develop many potential applications in biomedical fields and magnetic photocatalyst.