Theoretical and experimental study of Si,Al distribution rule in tectoaluminosilicate minerals

构造铝硅酸盐矿物中Si、Al分布规律的理论与实验研究

基本信息

批准号：
60430016
负责人：
SATO Mitsuo
金额：
$ 10.24万
依托单位：
Gunma University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

项目摘要

1. Characterization of Si,Al distributionSi,Al distribution on the tectoaluminosilicate frameworks was characterized by introducing a new concept of substituted concentric cluster(SCCL). It was disclosed that various kinds of Si,Al distribution on the framework are fairly reflected on the types and the frequencies of the SCCL , and the connective relations between Si and Al atoms are clearly visualized on the SCCL.2. Prediction of Si,Al distributionA graph theoretical derivation of the possible SCCLs was tried under the restriction of Loewenstein (avoidance rule of Al-Al pair in the 1st neighbor) as well as Dempsey rule (minimization rule of Al-Al pairs in the 2nd neighbor). The 1st SCCLs were obtained by an application of simplex method, while the 2nd SCCLs by using a mathematical vector relation . Si and Al distribution on a given framework could be predicted by assigning the above SCCLs on the framework. In order to avoid the production of infinite combinations of them. special attention was paied on the translational symmetry of the framework and the compatibility relationship of the SCCLs to be combined. 3-dimensional computer graphics method was newly developed for the procedure.3. Determination of Si,Al distribution by X-ray diffraction methodIn order to confirm the predicted Si,Al distribution , crystal structure of scapolite mineral, which forms a complete solid solution between Al/Si = 3 and 1 , was determined by X-ray diffraction method. Data were collected using a four circle automatic X-ray diffratometer, Rigaku AFC-M. Bond distances between T(Si,Al) and 0 atoms were closely examined and found that the T - 0 distance was significantly longer than the other T , T - 0 distaces. This indicated that the probability of Al occupancy at site 2 was very high. The distribution was completely consistent with one of the predicted ones.

1。tectoaluminosilicate框架上Si，al Distributionsi，Al分布的表征是通过引入新的替代同心群集（SCCL）的概念来表征的。据披露，框架上的各种Si，Al分布都在SCCL的类型和频率上得到了反映，并且在SCCL.2上清楚地看到了Si和Al Atoms之间的结缔关系。在Loewenstein的限制下（第一个邻居中Al-Al对的避免规则）以及Dempsey规则（第二个邻居中Al-Al Pairs的最小化规则），尝试了可能SCCL的Si，Al分布图理论推导。第一个SCCL是通过单纯形方法的应用获得的，而第二个SCCL则通过使用数学矢量关系获得。可以通过在框架上分配上述SCCL来预测给定框架上的SI和AL分布。为了避免产生它们的无限组合。特别注意框架的翻译对称性以及要组合的SCCL的兼容性关系。 3维计算机图形方法是为该过程新开发的。3。通过X射线衍射方法确定Si，Al分布的确定，以确认Scapolite矿物质的预测Si，Al分布，晶体结构，该矿物质在Al/Si = 3和1之间形成完整的固体溶液，通过X射线衍射方法确定。使用四圈自动X射线衍射仪Rigaku AFC-M收集数据。仔细检查了t（Si，al）和0原子之间的键距离，发现t -0距离明显长于其他t，t -0距离。这表明站点2的AL占用率很高。该分布与预测的分布完全一致。