| Summary: | 碩士 === 國立聯合大學 === 材料科學工程學系碩士班 === 101 === In this study, glasses with composition SiO2-B2O3-ZnO-Bi2O3 have been prepared. ZnO in glass was replaced by B2O3 or Bi2O3 respectively. The physical, optical and structural properties of the glasses were investigated.
Experimental results show that with the increase of B2O3, density, thermal expansion coefficient and the refractive index of glass decreased. Substitution of Bi2O3 for ZnO increased the density, molar volume, refractive index and thermal expansion coefficient of the glasses. While the glass transition temperature and the transmittance decreased with increasing Bi2O3 content.
Fourier transform infrared spectroscopy and Raman spectroscopy were used to study the influence of glass composition on glass structure. The vibration of [BO3] and [BO4] become stronger as the content of B2O3 increases, which shows that the B2O3 is a glass network former. With increasing Bi2O3 content, the vibration of [BiO6] unit becomes stronger significantly and the stretching vibration peaks of [BO4] unit shifted to low wave number, which means the damage of boron-oxygen structure and forms a new Bi‒O‒B bond. It shows that part of the Bi2O3 in the glass system is as a glass network former.
By analyzing Raman and FTIR spectra of SiO2-B2O3-ZnO-Bi2O3 glasses it was found that B3+ and Bi3+ cations are incorporated in the glass network as [BO3], [BO4], and [BiO6] units.
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