类质同象置换对云母晶体生长机制的影响与制约

Mica is a typical group of phyllosilicates with a 2:1 structure. They act as important and unique crystal materials in national defense, communication industries etc., based upon their physio-chemical properties, including large layer structure, superior dielectric properties, and high thermal stability. The utilization level of mica minerals greatly depends on the knowledge of their microstructural properties and crystal forming mechanism. This proposal focuses on the isomorphous substitution features and their effects on the crystal growth of minerals, which are widely concerned in mineral science. The comparisons between natural and synthetic samples will be studied by the combination of the field investigation and laboratorial micro-analysis techniques. On the basis of systematic studies of the crystal chemical characteristics and the crystal growth of mica minerals, the internal relations and the controlling factors will be revealed among their isomorphous substitutions features, the crystal defects and the polymorphism, and the crystal growth mechanism of mica minerals. The achievements of this proposal are of high importance for well understanding reserves differences among naturally occurred micas, efficient utilization of mica resources, and guiding synthesis of their analogues.

云母是一类典型的2:1型层状硅酸盐矿物。它们通常片层较大、易分剥，具有良好的介电性和较高的耐热性等理化性质，在国防、通讯等领域中发挥着重要和独特的作用。云母的利用水平取决于对其微结构和形成机理的深刻理解。为此，本申请拟以当前矿物学界非常关注的矿物结构中类质同象置换特征对其晶体生长机制的影响与制约为关键科学问题，从云母晶体化学特征入手，采用微束、微区表征技术，通过野外调查与室内表征相结合、天然样品与合成样品的比较，系统研究云母的晶体化学特征与生长机制间的内在联系；揭示云母矿物结构中类质同象置换特征及其影响因素；阐明类质同象置换特征对晶体缺陷、多型性之间的制约作用，以及它们对云母晶体生长机制的影响与制约机理。为理解不同种类云母矿物间资源量的差异性与物理化学性质的多变性等提供矿物学依据，为天然云母矿物资源的高效利用和云母矿物的合成提供理论支撑，具有重要的理论和经济意义。

云母是一类典型的2:1型层状硅酸盐矿物。它们通常片层较大、易分剥，具有良好的介电性和较高的耐热性等理化性质，在国防与通讯等领域中发挥着重要和独特的作用。本研究从云母晶体化学特征入手，采用微束、微区表征技术，通过野外调查与室内表征相结合、天然样品与合成样品的比较，系统研究了云母的晶体化学特征与生长机制间的内在联系。项目揭示了代表性云母族矿物结构中类质同像置换特征及其影响因素；采用熔融法成功合成了氟金云母，查明了实验条件对云母多型、结晶度和生长机制（螺旋生长和层堆垛生长等）的影响机制；查明了天然岩浆成因和变质成因的云母晶体结构中的缺陷、多型性等特征与成因，阐释了其对云母晶体生长的影响及其控制机理及其对地质过程的指示意义。发现并率先提出岩浆结晶过程中，云母纳米晶粒定向堆砌生长的新机制，突破了基于单原子/离子堆积的传统矿物生长理论，为理解元素地球化学行为、解析成岩成矿过程提供了新的理论支持。相关研究成果也为阐释层状硅酸盐矿物的特殊形貌和结构，以及功能纳米材料的合成提供了新思路，具有重要的理论和经济意义。