Preparation And Surface-modification Of The Rare-earth Luminescent Nanomaterials

Rare earth luminescent materials have become the main materials in information display,green light engineering and optical communication etc.because the rare earth ion has the special 4f and 4f5d electron energy level and charge transition state.When the grain size of the host is small to nanoscale,the rare earth luminescent materials will present a variety of characteristics such as broadened band,change in the fluorescent lifetime and the quenching concentration.These characteristics can improve greatly the properties and functions of the materials.There are a lot of troubles and limitations on preparing rare earth luminescent materials,so new preparing methods are required.In order to resolve the mentioned problems, synthesize nano-sized or nano-level rare earth luminescent material with fine particle and good luminescent properties is a hot research.In this thesis,rare earth nanomaterials(for example:LaPO₄:Eu³⁺,GdPO₄:Eu³⁺, GdVO₄:Eu³⁺,YPO₄:yb³⁺,Er³⁺) with different morphologies were synthesized by surfactant-assisted hydrothermal method.The structure and property were characterized by XRD,TEM,FTIR,PL,and some new results were obtained.Such as:surfactant system on the morphology of nanoparticles have a certain impact,with different morphologies also have an impact on the luminous intensity and so on.Coating nanoparticles had been studied widely for their special property on the material modification and new function.In this thesis,coating SiO₂ on the surface of the LaPO₄:Eu³⁺ nanorod by sol-gel method.Conditions can be controlled by changing the thickness of coating.The structure and property of coating were characterized by XRD,TEM,FTIR,PL.