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首页> 外文期刊>Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites >Structural study of bismuth borosilicate, aluminoborate and aluminoborosilicate glasses by ~(11)B and ~(27)Al MAS NMR spectroscopy and thermal analysis
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Structural study of bismuth borosilicate, aluminoborate and aluminoborosilicate glasses by ~(11)B and ~(27)Al MAS NMR spectroscopy and thermal analysis

机译：〜（11）B和〜（27）Al MAS NMR光谱学和热分析研究硼硅酸铋，铝硼酸盐和铝硼硅酸盐玻璃的结构

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摘要

Glasses of bismuth borosilicates, aluminoborates and aluminoborosilicates were prepared by melt quenching and characterized by density measurements, ~(11)B and ~(27)Al Magic Angle Spinning (MAS) Nuclear Magnetic Resonance (NMR) spectroscopy, and Differential Scanning Calorimetry (DSC). Increase in silica concentration increases density without any change in the fraction of tetrahedral borons (N_4) in the borosilicate glass network, whereas increase in alumina concentration in aluminoborate and aluminoborosilicate glasses drastically reduces density and N_4. ~(27)Al MAS NMR measurements revealed that Al ions are in four, five and six fold coordination with oxygen and about 47% of these are in ~([5])Al and ~([6])Al structural units, the concentration of the latter species decreases by adding silica in the glass network. Higher cation field strength of Bi~(3 +) generates very large concentration of non-bridging oxygens, which act as charge balancing centers in the glass network. DSC measurements found that alumina and silica incorporation in bismuth borate glasses do not produce any systematic changes in the glass transition temperature but the tendency towards crystallization decreases steadily.
机译：硼硅酸铋玻璃，铝硼酸盐和铝硼硅酸玻璃是通过熔融淬火制备的，并通过密度测量，〜（11）B和〜（27）Al魔角旋转（MAS）核磁共振（NMR）光谱以及差示扫描量热法（DSC）进行表征）。二氧化硅浓度的增加会增加密度，而硼硅酸盐玻璃网络中的四面体硼（N_4）的比例不会发生任何变化，而铝硼酸盐和铝硼硅酸盐玻璃中氧化铝浓度的增加会大大降低密度和N_4。 〜（27）Al MAS NMR测量显示，Al离子与氧具有四，五和六倍的配位作用，其中约47％位于〜（[5]）Al和〜（[6]）Al的结构单元中，通过在玻璃网络中添加二氧化硅，后一种物质的浓度降低。 Bi〜（3 +）的较高阳离子场强度会产生非常高浓度的非桥连氧，它们在玻璃网络中充当电荷平衡中心。 DSC测量发现，在硼酸铋玻璃中掺入氧化铝和二氧化硅不会在玻璃化转变温度中产生任何系统的变化，但是结晶的趋势稳定地降低。

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