Development of x-ray diffractometer for petrographic thin section

本研究的目的是建立一种方法，收集在光学显微镜下精确检查的岩相薄片上的小单晶的X射线衍射数据。2005年，准直器，通过该准直器，入射X射线被聚焦在共同的中心或phi-和chi-上，2006年，新设计了一台商用衍射仪的圆，并成功地进行了验证。来自巴西波科斯德卡尔达斯的云母正长岩薄片上的小颗粒碱性角闪石晶体的X射线衍射数据，其描述于Journal of Mineralogical and Petrological Sciences，vol.99，pp 59 -66，2004年由我们收集使用上述衍射仪装备的准直器。射线数据通常从相关材料的孤立颗粒收集，并且不必考虑入射射线的宽度。而薄片上的晶粒不是孤立的，而是有相邻的晶粒 ...更多信息 为了避免来自相邻颗粒的额外反射光束，应利用聚焦射线。为此，我们用φ 0.2mm的石英玻璃管制成准直器，并对准直器进行调整，使其聚焦于有关样品，在通常情况下，通过改变入射X射线和衍射X射线的方向，可以收集到单晶的一整套X射线衍射数据。然而，在目前的情况下，这些射线的方向是非常有限的，因为标本下的载玻片阻止了X射线的传播。为了克服这些限制，作者和他的同事开发了一种方法，该方法在理学电机杂志，第25卷，第1部分，第3 -9页（1994年）中进行了描述。根据该方法，具有连续能谱的白色X射线作为入射射线，并且固态检测器能够分辨衍射X射线的能量。倒易空间中的测量范围被选择到圆锥的内部，该圆锥的轴线垂直于薄切片的表面并且其垂直角为21度。将范围划分为12，227个小区域，并对单个区域的衍射X射线进行计数。获得了来自相关区域的1540个显著衍射强度。在薄片上，晶体内部似乎还存在着很大的应力场。测量数据的分析应在不久的将来进行减

The purpose of this investigation is to establish a method of a collection of x-ray diffraction data from a small single crystal on the petrographic thin section which has been examined precisely under the optical microscope.In 2005, the collimator by which incident x-rays were focused on the common center or phi- and chi-circle of a comercial diffractometer was newly designed and has been confirmed to work successfully.In 2006, the x-ray diffraction data from a small grain of an alkali amphibole crystal on the thin section of nepheime syenite from Pocos de Caldas, Brazil, which was described in Journal of Mineralogical and Petrological Sciences, vol.99, pp59-66, 2004 by us were collected using the above mentioned diffractometer eauipped the collimator.X-ray data are usually collected from an isolated grain of the relevant material and it is not necessary to consider the breadth of the incident rays. However, the grain on the thin section is not isolated but has the neighboring crystal … More grains around it. In order to avoid the extra reflected beams from the neighboring grains, focused rays should be utilized. For this reason, a collimator has been made using a flexible silica-glass tube of 0.2mm φ and has been tuned to focus the concerning specimen.In usual case, a whole set of the x-ray diffraction data of a single crystal is collected by varying the directions or tne inciaent x-rays and the diffracted x-rays. In the present case, however, the directions of those rays are very restricted because the slide glass under the specimen prohibits the propagation of the x-rays. To overcome the restrictions one of the writer and his coworkers developed a method which was described in Rigaku Denki Journal, Vol.25, Part1, pp3-9 (1994). According to this method, the white x-ray having the continuous energy spectra as the incident rays and the solid state detector which was enable to resolve the energy of the diffracted x-rays. The measured range in the reciprocal space was selected to the inside of a cone of which axis was normal to the surface of the thin section and its vertical angle was 21 degrees. The range was divided to 12,227 small areas and the diffracted x-rays from individual area were counted. 1540 significant diffracted intensities from relevant areas were obtained. Very large stress field seemed to remain in the crystals on thin section. The analysis of the measured data should be performed in near future Less