Preparation And Characterization Of Functional Materials

Functional materials, which have many excellent properties such as electrical, magnetic, optical, mechanical, thermal, acoustics, chemical, biological medicine and etc. Because of their unique physical, chemical and biological properties, functional materials can be used to fabricate functinal micro-devices, which has wide application in the field of high technology. Function materials attract many scientists of the world to research because of it importance in high technology.Herein, we focus on the synthesis of rare-earth luminescence materials, hollow materials, magnetic nano-materials and the nonlinear optical crystal materials by using hydrothermal method and solid-state reaction. The as-prepared samples have also characterized by using XRD, TEM, SEM, TGA and EDS. The reaction mechanisms are explained. The major content of master's thesis is as follows:1 The green fluorescent Zn₂SiO₄:Mn was prepared by a simple in-situ hydrothermal method using SiO₂ act as template. Through controlling the reaction conditions, the products with hollow and micro-flower structure were synthesised. The experiment studyed the morphology, when changing the Si:Zn molar radio, reaction time and reaction temperature.The samples were characterized by XRD, TEM, SEM, fluorescence spectroscope, and reaction mechanism was explained.2 A facile hytrothermal method was been employed to fabricated hollow-structure materials. This experiment's innovation is that the hollow materials is prepared under acidic condition, which is different from the report in the literature of alkaline condition. The samples have phenomemon of fluorescence, when doped the rare-earth. The reaction temperature and pH were studied. The as-prepared samples were characterized by TEM, SEM, and so on. Water-soluble Fe₃O₄ was coated by SiO₂ using St?ber method.3 Nonlinear optical crystal materials BaAlBO₃F₂(BABF)were synthesised by solid state reaction. The purity of the product was affected by the quantities of boric acid (H3BO3). The sample was analysised by XRD and fluorescence spectrometry, the results indicated that the rare-earth element had doped into the BABF. Characteristic blue and red fluorescence were seen.4 A new nonlinear optical material (BONO)has a large second harmonic generation (SHG) effect (about 10 more times of that of KDP). Reaction temperature, pH, surfactant were investigated in this experiment.