Spectroscopic studies on vitreous and polycrystalline heavy metal gallium–bismuthates

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• 作者：V. Simon ; O. Ponta ; D. Tr ; afir ; H. Mocuta
• 关键词：Glass ceramics ; Heavy metal oxides ; FTIR measurements ; Electron spin resonance
• 刊名：Journal of Non-Crystalline Solids
• 出版年：2009
• 出版时间：1 December 2009
• 年：2009
• 卷：355
• 期：50-51
• 页码：2451-2455
• 全文大小：475 K

文摘

Local order changes determined by Fe₂O₃ (0–20 mol % ) addition to Bi₂O₃–Ga₂O₃ matrix in glass and vitroceramic samples were investigated by X-ray diffraction (XRD), electron paramagnetic resonance (EPR) and Fourier transform infrared (FTIR) spectroscopies. Glass samples were prepared using the melt-quench technique. The vitroceramic samples were obtained by crystallization, as a result of the heat treatment applied on glass samples. The glass network mainly consists of [BiO₆] octahedral units. After heat treatment induced crystallization, [BiO₃] pyramidal units are predominant in samples. As evidenced by electron spin resonance, the Fe³⁺ ions surrounding is characterized by low crystal fields, excepting the vitreous sample with the lowest Fe₂O₃ content, wherein the Fe³⁺ ions occupy sites of low symmetry, characterized by high crystal fields.