| Summary: | 碩士 === 國立聯合大學 === 材料科學工程學系碩士班 === 94 === The objective of this study is to investigate the structure and properties of Er3+ or Er3+/Yb3+ codoped zinc aluminum fluorophosphates glass. A series of Er3+ or Er3+/Yb3+ codoped zinc aluminum fluorophosphates glasses have been prepared. The results indicate that the glass transition temperature (Tg), glass softening temperature (Ts), glass crystallization temperature (Tc), density, thermal stability, and chemical durability increase with increasing rare-earth content in the glass composition. The dissolution rate of Er3+/Yb3+ codoped zinc aluminum fluorophosphates glasses in this study is lower than that made by Kigre Company. It is successful to breakthrough the choke point that phosphate glass had weak chemical stability. In optical properties, the near-infrared emission band at 1.535 μm and red emission band at 645 nm of Er3+/Yb3+ codoped zinc aluminum fluorophosphates glass have been achieved by excitation with a 980 nm diode laser at room temperature. The absorption and emission intensity increase with Er3+ and Yb3+ ions content. However, when the concentration of Er2O3 is more than 1 mol%, the ion clustering effect will result in photoluminescence intensity quench. By comparing the strength of the excitation spectra at Er3+ and Er3+/Yb3+ codoped zinc aluminum fluorophosphates glass, it is found that Yb3+ ions really can be used to sensitize Er3+ ions. The concentration effect of Al2O3 on the zinc aluminum fluorophosphates glass is analyzed by Fourier transformed infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectrometer. From 31P spectrum, the peak value of chemical shift moves from negative to positive as Al2O3 concentration increases. It can be found that Q2 structure change to Q1 structure, and replaced by Q0 structure finally. The 31Al spectrum showed that aluminum ion exists in the coordination number of Al(6), Al(5) and Al(4) in the zinc aluminum fluorophosphates glass. The experimental results also indicate that the glass transition temperature (Tg), glass softening temperature (Ts), glass crystallization temperature (Tc), and water resistance increase but the density, refractive index and thermal expansion coefficient decrease with increasing rare-earth content in the glass composition.
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