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. Si、Al分布的表征通过引入取代同心簇（SCCL）的新概念，表征了结构铝硅酸盐骨架上Si、Al的分布。结果表明，骨架上各种Si、Al的分布很好地反映了SCCL的类型和频率，并且Si和Al原子之间的连接关系在SCCL上清晰可见。2。 Si,Al分布的预测在Loewenstein（第一个邻居中Al-Al对的避免规则）和Dempsey规则（第二个邻居中Al-Al对的最小化规则）的限制下尝试了可能的SCCL的图论推导）。第一个 SCCL 是通过应用单纯形法获得的，而第二个 SCCL 是通过使用数学向量关系获得的。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。以避免产生它们的无限组合。特别关注框架的平移对称性和要组合的 SCCL 的兼容性关系。为该程序新发展了三维计算机图形学方法。 3． X射线衍射法测定Si、Al分布为了证实预测的Si、Al分布，采用X射线衍射法测定了Al/Si=3和1之间形成完全固溶体的方沸石矿物的晶体结构。方法。使用四环自动 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，发现 T - 0 距离明显长于其他 T 、 T - 0 距离。这表明Al占据位置2的概率非常高。该分布与预测之一完全一致。