在酸盐玻璃中混合Mg协调环境的证据:来自25Mg NMR光谱在35.2 T的结果
Sabyasachi Sen1, Jonathan F Stebbins2, Scott Kroeker3
1Department of Materials Science and Engineering, University of California at Davis, Davis, California 95616, United States.
The journal of physical chemistry. B
|November 30, 2023
概括
超高场25Mg NMR揭示了酸盐玻璃中的4倍和6倍协调. 这解决了长期以来关于这些材料中的协调的争议.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 频谱学是一种光谱学.
背景情况:
- 了解酸盐玻璃中的协调对于材料科学至关重要.
- 以前使用衍射和X射线吸收光谱的研究产生了关于Mg协调的有争议的结果.
- 土和酸玻璃具有不同的结构性质.
研究的目的:
- 精确确定各种酸盐玻璃中的Mg-O协调环境.
- 解决了围绕基土酸盐玻璃中Mg协调的长达十年的争议.
- 为了研究酸盐对Mg协调的影响.
主要方法:
- 使用超高场 (35.2 T) 25Mg魔力角旋转 (MAS) 的NMR光谱.
- 采用三次量子MAS NMR光谱学来提高光谱分辨率.
- 分析具有CaMgSi2O6,Na2MgSi3O8和K2MgSi5O12组成的酸盐玻璃.
主要成果:
- 在所有研究的眼镜中,Spectra 清楚地表明了 4 倍 (MgIV) 和 6 倍 (MgVI) 协调的 Mg 的共存.
- MgIV/MgVI比率表明CaMgSi2O6玻璃的平均Mg-O协调数为~5,使NMR数据与先前的衍射和X射线吸收结果保持一致.
- 在-Mg酸盐玻璃中,Mg-O协调数降至~4.5,表明Mg与酸盐竞争非桥接氧基.
结论:
- 超高场NMR光谱学有效地解决了酸盐玻璃中的Mg协调,解决了长期以来的争论.
- 协调受到酸盐的存在的影响,Mg有利于四面体协调.
- 这项研究强调了先进的NMR技术在具有挑战性的材料结构分析方面的潜力.
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