Niobium alkali germanate glasses were synthesized by the melt-quenching technique. The ternary system (90-x)GeO2-xNb2O5-10K2O forms homogeneous glasses with x ranging from 0 to 20mol%. Samples were investigated by DSC and XRD analysis, FTIR and Raman spectroscopy, and optical absorption. Structural and physical features are discussed in terms of Nb2O5 content. The niobium content increase in the glass network strongly modifies the thermal, structural and optical properties of alkali germanate glasses. DSC, Raman and FTIR analysis suggest niobium addition promotes NbO6 groups insertion close to GeO4 units of the glass network. XRD analysis also pointed out that samples containing high niobium oxide contents exhibit preferential niobium oxide rich phase after crystallization after heat treatment, which is similar to orthorhombic Nb2O5. Absorption spectra revealed high transmission range between 400nm to 6.2μm, added to a considerably decreased hydroxyl group content as the addition of niobium in the alkali germanate network. The niobium oxide rich phase crystallization process was studied and activation energy was determined, as well as nucleation and crystal growth temperatures and time for obtaining transparent glass-ceramics. This article is protected by copyright. All rights reserved.

中文翻译：

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锗酸盐玻璃中的高铌氧化物含量：热、结构和光学特性

采用熔融淬火技术合成铌碱金属锗酸盐玻璃。三元体系 (90-x)GeO2-xNb2O5-10K2O 形成均质玻璃，x 范围为 0 至 20 mol%。通过 DSC 和 XRD 分析、FTIR 和拉曼光谱以及光吸收来研究样品。根据 Nb2O5 含量讨论结构和物理特征。玻璃网络中铌含量的增加极大地改变了碱金属锗酸盐玻璃的热、结构和光学性能。DSC、拉曼和 FTIR 分析表明，铌的添加促进了 NbO6 基团插入接近玻璃网络的 GeO4 单元。XRD 分析还指出，含有高铌氧化物含量的样品在热处理后结晶后表现出优先的富铌相，类似于正交 Nb2O5。吸收光谱显示在 400nm 到 6.2μm 之间的高透射范围，随着在碱金属锗酸盐网络中添加铌，羟基含量显着降低。研究了富铌相结晶过程并确定了活化能，以及获得透明微晶玻璃的成核和晶体生长温度和时间。本文受版权保护。版权所有。本文受版权保护。版权所有。本文受版权保护。版权所有。