Fabrication And Properties Of Y_xgd_2-xo₃:eu Powders And Nano-sized Fe₃o₄/y₂o₃:eu Core-shell Materials

In recent years, much attention has been paid to fabrication of core-shell materials in the field of material science. Core-shell materials, often made up of a solid core surrounded by a well-defined shell layer, are known to exhibit unique and advanced properties over single-component materials, making them attractive for use in a wide range of applications. The structure, size, and composition of these materials can be easily altered in a controllable way to tailor their magnetic, optical, mechanical, thermal, electrical, and catalytic properties.In this thesis,it has been focused on study of core-shell magnetic materials and luminescent materials. This study is attempted to fabricate core-shell Fe3O4/Y2O3:Eu nanospheres with multifuctions.On one hand, It has been reported thatYttrium-89 (100% natural abundance) may be activated toβ-emitter 90Y with a half-life of 64.1 h by neutron bombardment,it is expected that Yttrium-89 in core-shell FeaO4/Y2O3:Eu nanospheres are useful for in situ radiotherapy of cancer. On the other hand, core-shell Fe3O4/Y2O3:Eu nanospheres containing the magnetic Fe3O4 nanoparticles may act as platforms to deliver externally activable drugs or therapeutic agents and also produce a new targeted therapeutic effect:the selective destruction of targeted cancer cells in a magnetic field.On the other hand, core-shell Fe3O4/Y2O3:Eu nanospheres still retained red luminescent properties of Y2O3:Eu. In addition, it was employed Gd doping to enhance photoluminescence properties of Y 2O3:Eu nanopowders.and novel fluorescence properties of YxGd2-xO3:Eu bring opportunities to labeling technique in biomedical fields.The thesis major explored in the following aspects:a. Through the analysis of preparation mechanism of nanoparticles, the chemical coprecipitation method was adopted to prepare magnetic Fe3O4 nanoparticles. The morphology, structure and magnetism of the particles were investigated. b. Fe3O4Y2O3, Fe3O4/Y2O3:Eu core-shell structure materials were successfuly prepared by using Fe3O4 spheres as templates. Not only had the core-shell structure Fe3O4/ Y2O3:Eu nanospheres paramagnetism, but also still retained red luminescent properties of Y2O3:Eu. In the meantime, Influence of Gd doping on the photoluminescence enhancement ofY2O3:Eu (Eu3+doping molar concentration is kept as 5%) nanocrystals prepared by homogeneous precipitation method was investigated.c. The prepared samples were detected by X-ray diffraction(XRD), transmission electron microscope(TEM),scan electron microscope(SEM),FIIR spectroscopy, vibrating sample magnetometer(VSM), luminescence spectroscopy (LS) etc. related properties of samples were characterized and discussed.