Abstract The full and congruent crystallization of the Bi0.8Nb0.8Te2.4O8 (BNT) glass leads to perfectly transparent ceramic in both the visible and near infrared ranges. While heating the parent glass, an intermediate structural regime order – called anti-glass – that shows chemical inhomogeneity at the nanometer scale and with a long-range cationic ordering while retaining a strong local anionic disorder is observed. Here, we report on the crystallization sequence starting from the Bi0.8Nb0.8Te2.4O8 glass system and show that an intermediate Bi0.8Nb0.8Te2.4O8 anti-glass phase (polymorph 1) is first formed, before transforming into a more ordered and ceramic material (polymorph 2). In particular, we provide a comprehensive structural study of the crossover between glass and its crystalline counterpart through intermediate steps. Similarities and differences between the structures, microstructures of Bi0.8Nb0.8Te2.4O8 glass, anti-glass and ceramic materials of identical composition are investigated in details at different length scales by X-ray and neutron powder diffraction, SEM-EBSD, TEM, NMR and Raman spectroscopy. The optical properties of the anti-glass and ceramic are discussed in correlation with the structure and microstructure observations. This study paves the way for understanding the complex mechanisms at the origin of the full and congruent crystallization from the parent glass.

中文翻译：

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Bi2O3-Nb2O5-TeO2体系中玻璃/半透明反玻璃/透明陶瓷结构有序性的综合研究

摘要 Bi0.8Nb0.8Te2.4O8 (BNT) 玻璃的完全一致结晶导致了在可见光和近红外范围内完全透明的陶瓷。在加热母体玻璃时，观察到一种中间结构有序——称为反玻璃——在纳米尺度上显示出化学不均匀性，并具有长程阳离子有序性，同时保留了强烈的局部阴离子无序。在这里，我们报告了从 Bi0.8Nb0.8Te2.4O8 玻璃系统开始的结晶序列，并表明首先形成中间 Bi0.8Nb0.8Te2.4O8 抗玻璃相（多晶型 1），然后转变为更有序的相和陶瓷材料（多晶型 2）。特别是，我们通过中间步骤对玻璃与其结晶对应物之间的交叉进行了全面的结构研究。通过X射线和中子粉末衍射、SEM-EBSD、TEM，在不同长度尺度上详细研究了Bi0.8Nb0.8Te2.4O8玻璃、抗玻璃和陶瓷材料的结构、微观结构之间的异同，核磁共振和拉曼光谱。与结构和微观结构观察相关地讨论了抗玻璃和陶瓷的光学特性。这项研究为理解母体玻璃完全一致结晶起源的复杂机制铺平了道路。与结构和微观结构观察相关地讨论了抗玻璃和陶瓷的光学特性。这项研究为理解母体玻璃完全一致结晶起源的复杂机制铺平了道路。与结构和微观结构观察相关地讨论了抗玻璃和陶瓷的光学特性。这项研究为理解母体玻璃完全一致结晶起源的复杂机制铺平了道路。