铝硅酸盐矿物和玻璃中Al的配位与局部结构  

COORDINATION AND LOCAL STRUCTURE OF ALUMINUM IN ALUMINOSILICATE MINERALS AND GLASSES

作　　者：彭明生[1] 李迪恩[1] 张恩 彭建平[1] 

机构地区：[1]中山大学宝石矿物材料研究所,广州510275

出　　处：《矿物学报》1998年第4期425-430,共6页Acta Mineralogica Sinica

基　　金：国家自然科学基金!49572094

摘　　要：利用同步辐射的AlK边X射线吸收近进结构（XANES）谱研究了刚玉和铝硅酸盐矿物（蓝晶石，红柱石，夕线石和钠长石）中Al的配位与局部结构，证明该方法可以作为新的结构探针研究结构未知体系中Al的配位与局部结构。例如，Al的K边XANES谱证明在室温压条件，钠长石玻璃中的Al保持为四面体配位（AlIV），局部结构与钠长石晶体中的Al相似；尽管硬玉晶体中的Al为八面体配位，但硬玉玻璃中的Al变为四面体配位（AlIV）。而在相同的高温压条件（4．4GPa，1575C）下制备的硬玉-钠长石玻璃系列中，压力引起四面体配位的Al变成五次（Alv）和六次配位（AlVl），且五次和六次配位Al的比例随玻璃中硬玉含量的增加而增大。Synchrotron radiation Al K-edge X-ray absorption near-edge structure (XANES) has been applied to studying the coordination and local structure of Al in corundum and aluminosilicate minerals (kyanite, andalusite, sillimanite and albite). This technique has proven itself to be a new and useful structure probe for studying the coordination and local structure of Al in the systems of unknown crystal structure. For example, Al Kuedge XANES spectra showed that at ambient con-dition, Al in albite and jadelte glasses is four-fold coordinated with oxygen, and lts local structure is similar to that in albite crystal, even though Al is slx-fold coordinated with oxygen in jadeite crystal. However, in high temperature and pressure (4. 4 GPa and 1 575 ℃) albite-jadeite glass se-ries, high pressure induces coordination changes of Al from four-fold to five- and slx-fold, and the proportions of five- and six-fold coordinated Al increase with increasing content of jadeite composi-tion.

关 键 词：铝硅酸盐矿物 玻璃 配位 结构 铅 

分 类 号：P578.94[天文地球—矿物学] TQ171.718[天文地球—地质学]