Magnetic and luminescent hybrid nanomaterial based on Fe _3O _4 nanocrystals and GdPO _4:Eu ~(3+) nanoneedles

摘要

A bifunctional hybrid nanomaterial, which can show magnetic and luminescent properties, was obtained. A magnetic phase was synthesized as a core/ shell type composite. Nanocrystalline magnetite, Fe 3O 4 was used as the core and was encapsulated in a silica shell. The luminescent phase was GdPO 4 doped with Eu 3+ ions, as the emitter. The investigated materials were synthesized using a coprecipitation method. Encapsulated Fe 3O 4 was "trapped" in a nanoscaffold composed of GdPO 4 crystalline nanoneedles. When an external magnetic field was applied, this hybrid composite was attracted in one direction. Also, the luminescent phase can move simultaneously with magnetite due to a "trapping" effect. The structure and morphology of the obtained nanocomposites were examined with the use of transmission electron microscopy and X-ray powder diffraction. Spectroscopic properties of the Eu 3+-doped nanomaterials were studied by measuring their excitation and emission spectra as well as their luminescence decay times.