Studies on imperfection and phase transformation in crystalline minerals

晶态矿物中的缺陷和相变的研究始于1995年，此后一直在进行。本课题的研究内容是：(1)研制一套漫散射分析系统；(2)为我们的衍射系统配备单色仪和新的探测器，以指导适用于漫反射测量的系统；(3)测量某些材料的漫散射，并对测量数据进行分析。在第一个课题上，德国汉诺威大学的拉赫曼教授建议我们合作分析我们多年来一直在研究的镁铝镁石族衍射谱中的漫射散射。拉赫曼教授开发了一个强大的系统，可以用计算机模拟和重建漫反射散射，他想让他的系统适应我们的问题。1996年，我们开始了与…的合作此外，该系统还适用于分析无公度结构，进而模拟在镁铁线石族矿物的衍射谱中观察到的漫射散射。这项研究的一名研究人员仍在汉诺威大学研究这些问题。在第二个主题上，我们构建了一个测量漫反射散射的系统。在一台高功率(12kW)X射线发生器上安装了晶体单色器(石墨和硅)，并研制了一台配有成像板盒带的魏森伯格相机。在第三个课题上，我们测定了镁镁铁铝尖晶石[Ca_2MgSi_2O_7]和镁石固溶体[Ca_2(Mg，Fe)Si_2O_7]的无公度结构，并在五维空间中进行了描述。一篇关于后者无公度结构的晶体化学讨论的论文已经提交给了一份期刊。漫射散射的模拟结果已提交给1997年在汉堡举行的德国晶体学会年会。由于镁铝尖晶石固溶体样品在显微镜下含有一些不同延迟的磁区，我们用同步辐射测量了不同磁区的弥散散射，目前正在对其进行分析。为了弄清非公度调制的起源，我们还用分子轨道方法对漫射散射进行了模拟，得到了初步的结果。关于Al和Fe氢氧化物的脱水产物，我们的研究人员正在分析汉诺威大学的扩散散射。较少

The research on imperfection and phase transformation in crystalline minerals started in 1995 and has been undertaken ever since. The subjects of the research are (1) to prepare a system for analyzes of diffuse scattering, (2) to equip our diffraction system with monochromators and new detect in order to direct the system suitable for measurements of diffuse scattering, and (3) to measure diffuse scattering of some materials and to analyze the measured data. The results obtained up to the present and the research being in progress are as follows.On the first subject, prof.Rahman of the university of Hannover, Germany, proposed us to collaborate with each other on analyzes of the diffuse scattering found in diffraction patterns of akermanite group on which we have worked in these several years. Prof.Rahman had developed a powerful system to simulate and reconstruct diffuse scattering by computers and wanted to adapt his system to our problems. In 1996 we have started our collaboration t … More o adapt the system for analyzes of incommensurate structures and then to simulate diffuse scattering observed in the diffraction patters of akermanite group minerals. One of the investigators of this research is still working in the University of Hanover on these problems.On the second subject, we have constructed a system to measure diffuse scattering. Crystal monchromators (graphite and Si) were installed on a high-power X-ray generator (12kW) and a Weissenberg camera equipped with a cassette for'Imaging plate' was newly developed. The system is working for measurement of diffuse scattering now.On the third subject, we have determined the incommensurate structures of akermanite [Ca_2MgSi_2O_7] and of akermanite solid solution [Ca_2 (Mg, Fe) Si_2O_7] with the description in five-dimensional space. A paper of a crystal-chemical discussion of the incommensurate structure of the latter has been submitted to a journal. Results of the simulation of the diffuse scattering was presented to the annual meeting of German Crystallographic Association in 1997 at Hamburg. Since samples of akermanite solid solution include some domains with different retardation under a microscope, we measured diffuse scatterings from different domains with synchrotron radiation and we are analysing them now. We are also making simulation of the diffuse scattering by a molecular orbital method in order to clarify the origin of the incommensurate modulation, and we could get preliminary results. On dehydration products of hydro-oxides of Al and Fe, our investigator is analysing the diffuse scattering at the University of Hannover now. Less