稀土掺杂硼铝硅酸盐玻璃结构的NMR研究

在Sm₂O₃掺杂BaO-B₂O₃-Al₂O_3-SiO_2-Sm₂O₃(BBASS)玻璃系统的形成性能研究的基础上，借助MAS NMR以及差热测试(DTA)技术，研究了玻璃的结构特点以及玻璃组成、热处理条件等因素对玻璃结构的影响. 研究表明，在未掺稀土的BBAS玻璃结构中，硼氧多面体主要以BO₃]、BO₄]存在，铝氧多面体主要以AlO₄]、AlO₅]、AlO₆]存在；随着BBAS中BaO含量的增加，硼氧三角体BO₃]逐渐向BO₄]转变，原先AlO₄]、AlO₅]、AlO₆]共存的铝氧多面体结构逐渐转变为大量AlO₄]和少量AlO₅]共存的结构；稀土Sm³⁺具有较强的积聚作用，其能促使玻璃结构中的硼氧多面体形成巨大的网络结构；热处理对玻璃结构中硼氧多面体和铝氧多面体的配位结构影响不大.

Rare Earth Doped Boroaluminosilicate Glass Studied by Magic Angle Spinning Solid State NMR Spectroscopy

Forming performances of Sm-2O-3 doped BaO-B-2O-3-Al-2O-3-SiO-2-Sm-2O-3 (BBASS) glass systems have been assessed in previous studies. In this study, magic angle spinning (MAS) NMR spectroscopy and differential thermal analysis (DTA) test were employed to characterize glass structure and to study the factors affecting glass structure, such as glass composition and conditions for heat-treatment, in such glass systems. In BBAS glass without rare earth doping, the boron coordination were mainly BO-3] and BO-4] and the aluminum coordination were mainlyAlO_4], AlO_5] and AlO_6]. It was found that, with the increase of BaO content in the BBAS glass, BO-3] gradually became BO-4], and AlO-5]/AlO-6] gradually changed to AlO-4]. Sm+{3+} could accumulate in the glass with large amount, facilitating BO-4] to form a large network. It was also found that heat-treatment had little or no effect on the boron and aluminum coordination in the glass structure.