Near-infrared Optical Properties Of Transparent Oxide Glass-ceramics

The transparent oxide glass-ceramic is one kind of functional composite materials that combine the advantages of oxide glass and optoelectronic functional nano-material.The material possesses good chemical stability,thermal stability,fine mechanical processing performance of oxide glasses and unique excellent properties of semiconductor nanomaterials,so it has widely application in many fields,such as architecture,air craft,electronic and so on.In recent years,rare-earth and transition metal ions doped ZnAl₂O₄nanocrystals have been synthesized and their optical properties have been reported.However,since ionic radii of rare-earth ions are far larger than those of general metal ions in most case,concentration of rare-earth or transition metal ions in the ZnAl₂O₄nanocrystals was small and those doped ZnAl₂O₄ nanocrystals remained the spinel structures.Owing to low loss and tunable concentration of carriers,semiconductor-based plasmonic materials have good potential application in infrared optical devices.Zinc oxide is a kind of wide bandgap semiconductor materials,with unique optical and electrical properties and easily doped.Recently,the localized surface plasmon resonance?LSPR?phenomenon in Al³⁺,Ge⁴⁺and Ga³⁺-doped ZnO nanocrystals has been studied.As mentioned above,two kinds of transparent oxide glass-ceramics were successfully precipitated through melt-quenching and subsequent heat-treatment method.The study on the effects of doping ions on the structure and spectroscopic properties of oxide nanocrystals in the glasses were conducted in this thesis.The conclusions are as follows:?1?In the 58SiO₂-16[?1-x%?Al₂O₃+x%Yb₂O₃]-15ZnO-7Li₂CO₃-4TiO₂-0.2Sb₂O₃?mol%?system,pure ZnAl₂O₄ spinel nanocrystals were formed in the glasses without Yb₂O₃ doping.As the doping concentration of Yb₂O₃ increased,Yb³⁺ions were incorporated into the zinc aluminate nanocrystals and gradually changed the structure of space group of zinc aluminate from Fd m to F432.The incorporation of Yb³⁺ions into the nanocrystals formed in the glasses and subsequent structural variation induced the splitting of the absorption bands of Yb³⁺ions in the infrared range.?2?In the 42SiO₂-10.5Al₂O₃-10.5K₂O-37[?1-x%?ZnO+x%SnO]?mol%?system,Sn were incorporated into the ZnO nanocrystals and changed the microstructure of ZnO nanocrystals in the glass-ceramics.As the doping concentration of SnO increased,the morphology of nanocrystals formed in the glass-ceramics changed from spherical to dumbbell-like and twig-like.Glass-ceramics containing Sn doped ZnO nanocrystals were highly transparent in the visible spectral range,and showed strong absorption in the infrared spectral range due to the localized surface plasmon resonance.