【作者】 潘峰；

【导师】 莫宣学；

【作者基本信息】 中国地质大学（北京） ， 岩石学、矿物学、矿床学， 2006， 博士

【摘要】 硅酸盐熔体和硅酸盐矿物材料在冶金、材料和地球科学领域中应用非常广泛，硅酸盐矿物及硅酸盐熔体微结构的研究一直是冶金、材料和地球科学中一个重要的研究方向。拉曼（Raman）光谱和高温Raman光谱技术作为现代物质分子结构研究的重要方法，广泛应用于硅酸盐微结构的研究领域，并获得大量研究成果。 本论文是依托上海大学、中国地质大学（北京）和北京大学共同申请和执行的国家自然科学基金重点项目“高温Raman谱创新技术及高温下物质微结构与性能”完成的。其研究目标和任务是应用Raman光谱和高温Raman光谱技术，对硅酸盐矿物及其熔体的结构进行研究，原位和实时地测定硅酸盐及铝硅酸盐体系在升温和冷却过程中的Raman光谱，并结合量子力学和量子化学从头计算的方法，探讨铝对硅酸盐Raman光谱的影响及铝硅酸盐Raman光谱中各特征谱峰的结构含义，为阐明Al³⁺（包含四配位和六配位两种情况）在硅酸盐结构中的作用提供可靠的分析资料和拉曼光谱数据，也为硅酸赫熔体结构和矿物结构的研究提供了方法学方面的借鉴和参考。本论文取得的主要进展如下： 对11种具代表性的铝硅酸盐矿物品体进行了Raman光谱测定，采用Materials studio软件中的Dmol³密度泛函（DFT）量子力学软件对各个矿物晶体的晶胞单元进行模拟计算，并对实验和计算所得Raman光谱进行了对比分析。按照K₂O-Al₂O₃-SiO₂三元系相图，配置了具不同摩尔比的钾铝硅酸盐玻璃样品，分别在常温和高温下测定了这些样品的玻璃态与熔体态的Raman光谱。运用Gaussian98W软件，对一组成分上具有递变规律的（Si，Al）-O四面体聚集体结构模型进行了量子化学从头计算，并对实验和计算所得Raman光谱进行了对比分析。研究表明： 1、铝硅酸盐矿物晶体、玻璃和熔体的Raman谱图具有相似的变化规律：随四配位铝进入硅氧四面体数量的增多，800-1200cm^-1波数区间内特征谱峰明显地向低频方向移动，700-800cm^-1波数区间内出现谱峰，且光谱振动逐渐增强。前者的谱峰是由Si-O_nb间非桥氧的对称伸缩振动引起，但Al^Ⅳ-O四配位铝的振动并不在800-1200cm^-1波数区间，后者的谱峰归属于Al^Ⅳ-O_nb间非桥氧引起的对称伸缩振动；当六配位铝作为金属阳离子起网络修饰子作用时，会引起800-1200cm^-1波数区间内的谱峰向高频方向迁移。 2、在K₂O-Al₂O₃-SiO₂三元钾铝硅酸盐玻璃体系中，Al³⁺呈四配位作为网络形成子时，随Al₂O₃替代SiO₂含量的增加，体系的聚合程度增强，它在铝硅酸盐中起聚合作用。800-1200cm^-1波数区间内，较宽的谱峰包络线中含有丰富的结构单元Q₂、Q₃和Q₄，其中Q₃含量＞50％占主导地位，表明结构体系内含有大量以不同方式连接的Q₃结构单元，而解谱所得1150cm^-1波数的谱峰应是Q₃和Q₄协同作用的结果。 3、熔体与玻璃具有相似的结构，但也存在差别。在钾铝硅酸盐熔体微结构中，存在的Q₄，Q₃和Q₂三种结构单元处于动态平衡之中（如2Q₃＜=＞Q₄+Q₂），随温度升高将使反应向右进行。更多还原

【Abstract】 Silicate melts and minerals are widely applied to metallurgy, material science and geology. Thus studies on the structure and properties of silicate minerals, glasses and melts are of great importance in these fields. Raman spectroscopy and high-temperature Raman spectroscopy （HTRS） have widely been recognized as one of the most effective methods to study silicate microstructure, especially structure of silicate melts. Many significant research achievements have been obtained.This dissertation is supported by the Key Project of the National Natural Science Foundation of China "High-temperature Raman Spectroscopy （HTRS） and the Structure and Properties of Substance in High-temperature", which are jointly carried out by Shanghai University, China University of Geosciences （Beijing） and Peking University. The research intends to conduct studies on microstructure of silicate minerals and melts by using Raman and high-temperature Raman spectroscopy, including measuring Raman spectra of silicate and aluminosilicate minerals, glass and melts, calculating structure models by quantum mechanics and ab initio calculation of quantum chemistry and then comparing both experimental and calculating results. It aims to get better understanding about the role of Al³⁺ （including four-coordinate, six-coordinate） in silicate microstructure and its effects on the characteristics of Raman spectra of aluminosilicates, and to provide a hint in methodology for study of melt structure of silicates as well.Raman spectra of eleven typical aluminosilicate minerals were measured. By employing Dmol³ Density Functional Theory （DFT） software in Materials Studio3.1 packet, corresponding modeling was also conducted and then compared with the experimental results. Aluminosilicate glass samples with different compositions and mole ratios in K₂O-Al₂O₃-SiO₂ system were prepared and then measured with Raman spectrometer and High-temperature Raman spectrometer to get Ramam spectra for glass and melts, respectively. Meanwhile, polymerization models with various combinations of （Si, Al）-0 tetrahedrons were calculated by using software Gaussian 98W, i.e., ab-initio calculation of the quantum chemistry, and Compared with experimental results. The following conclusions can be reached on the basis of studies mentioned above.1. Similarities of Raman spectra among aluminosilicate crystals, glass and melts have been found. While frequencies of the characteristic peaks considerably decrease within the range of 800-1200 cm^-1, intensities of vibration increase within the range of 700-800 cm^-1 with increasing content of four-coordinated Al cations. While Raman scattering bands in the former range are assigned to Si-O_nb symmetric stretching vibrations, those in the range of 700-800 cm^-1 attributed to Al-O_nb symmetric stretching vibrations. The Raman bands within the range of 800-1200 cm^-1 shift to higher frequency if Al are six-coordinated cations as network modifiers.更多还原