二氧化硅新物相-斜硅石的研究现状综述

发布时间：2018-04-10 09:03

  本文选题：斜硅石　切入点：二氧化硅　出处：《矿物学报》2017年Z1期

【摘要】：斜硅石(moganite)是1999年才在国际上被正式承认为二氧化硅的新矿物种类,科学家们对其的研究还不深入。本文综述了斜硅石的晶体结构、高温热力学行为、物理化学性质以及理论计算的研究现状。同时,结合当前研究进展,讨论了斜硅石研究中亟待解决的关键科学问题,并且阐述了斜硅石研究的重大科学意义。斜硅石广泛存在于石英共生矿物中,目前纯相斜硅石还没有被发现。斜硅石有较高的含水量(约2%~4%),主要以自由水和羟基的形式存在,特别地,羟基以缺陷的形式存在于斜硅石晶格中。在高温热行为方面,斜硅石在570 K发生I2/a—Imab的可逆结构相变,类似石英中由软模驱动的α-β位移型相变,然而,由于目前缺少直接的实验证据支撑,其相变机理仍悬而未决,对于斜硅石在二氧化硅相图中的位置仍不明确。地质学上,斜硅石被认为是矿物在蒸发环境下结晶的证据,在成岩过程中具有十分重要的作用。尽管斜硅石在众多二氧化硅矿物中均被发现,但对于斜硅石在其结构演化中的关键作用仍不清楚,认识斜硅石在这些地质过程中的科学价值,需要了解其高温、高压特性和稳定性,而该方面的研究有待深入开展。
[Abstract]:Orthosilicate is a new type of mineral that was officially recognized as silica in 1999, and scientists have not studied it in depth.In this paper, the crystal structure, high temperature thermodynamic behavior, physical and chemical properties and theoretical calculation of orthosilicate are reviewed.At the same time, combined with the current research progress, the key scientific problems that need to be solved urgently in the research of orthosilicate are discussed, and the great scientific significance of the study of orthosilicate is expounded.Orthoclase is widely found in quartz symbiotic minerals.Orthoclase has high water content (about 2%), mainly in the form of free water and hydroxyl groups, especially in the form of defects in the lattice of orthosilicate.In the aspect of high temperature thermal behavior, the reversible structural phase transition of I2/a-Imab occurs at 570K, which is similar to the 伪-尾 displacement phase transition driven by soft mode in quartz. However, due to the lack of direct experimental evidence at present, the mechanism of the phase transition is still unresolved.The position of orthosilicate in the silica phase diagram is still unclear.Geologically, orthosilicate is considered as evidence of mineral crystallization in evaporative environment and plays an important role in diagenesis.Although orthosilicate has been found in many silica minerals, its key role in structural evolution is still unclear. Understanding the scientific value of orthosilicate in these geological processes requires understanding its high temperature.High pressure characteristics and stability, but this aspect of research needs to be further developed.
【作者单位】： 西安交通大学前沿科学技术学院;西安交通大学电子与信息工程学院;西安交通大学理学院;中国工程物理研究院材料研究所;
【基金】：国家自然科学基金项目(编号:41372055) 中国工程物理研究院材料研究所特聘基金(编号:TP201601-01)
【分类号】：P578.4
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本文编号：1730558