| Summary: | 碩士 === 國立聯合大學 === 材料科學工程學系碩士班 === 98 === This study explores optical, thermal and structure of properties of Li2O added P2O5-Nb2O5-SrO glasses. We add Li2O to replace SrO, and change the ratio of P2O5 to Nb2O5 of the glasses.
The increase in Nb2O5 contents will increase the density, glass transition temperature(Tg), refractive index and chemical durability. While the increase in Li2O contents leads to the decrease in density, molar volume, glass transition temperature and refractive index. Li2O can improve transparency lessen coloring effect due to Nb and blue-shift the UV cut-off wavelength. Due to the performances that refractive index can reach 1.8, Tg is lower than 550℃ and transmittance higher than 80%, respectively, our glasses are potential for use an molding lenses.
In structure analysis, we apply Fourier-transformed-infrared spectrometer, Raman spectrometer, solid state nuclear magnetic resonance and X-ray photoelectron spectrometer. The increase Li2O will dissociate P-O-P linkage. With the decrease in P2O5 content, the number of phosphate chains were reduces. While the increase in Nb2O5 content, resulte in P-O-Nb and Nb-O-Nb bonding, which affect the basic properties to enhance interconnect-density of glass network structure. Thus, even with a small content of phosphate, the glass still maintains the stability of glass network structure.
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