Application of X-rays to characterization of ultramicro samples and micro areas

1.本文用X射线衍射仪、弯曲位置灵敏正比计数器和三维测角仪研究了含有几种具有明显热各向异性晶体的耐热瓷和微晶玻璃中的晶体取向和分布。瓷板表面主要含有3-石英固溶体的微晶。随着远离地表，3-石英固溶体数量迅速减少，而顽火辉石和茚二石微晶增多。在距离表面200 μ m以上的内部均匀分布着Indialite和顽火辉石的微晶。这表明通过减小晶粒尺寸和改变表面附近的微晶分布来提高抗热震能力的可能性。在两种微晶玻璃的情况下，几乎相同的X射线微衍射（XRMD）图案从板的任何位置获得。这表明它们的晶体成分的随机取向和均匀分布，这解释了它们上级的抗热震性.制备了具有可更换铜线的黄铜样品保持器，用于小样品的XRMD分析。将在显微镜下分选的气载微粒中的单个颗粒用粘合剂粘在保持器的金属丝尖端上，并使用X射线显微衍射仪进行分析。它可以清楚地识别空气中颗粒物样品中大量的次要成分，甚至是小到0.03微克的颗粒。例如，在渡口降尘中检测到了超微量的金云母和莫来石。还表明渡口降尘中含有多种不同形态的磁铁矿，在黑色颗粒和碎片中是主要成分，在红黑色聚集体和黑色球体中是次要成分; 2赤铁矿、方解石和莫来石也是如此。

1. Crystalline orientation and distribution in plates of heat-resistant porcelain and glass ceramics containing some kinds of crystals with marked thermal anisotropy were studied by use of an X-ray microdiffractometer with a curved position sensitive proportional counter and a three-dimensional goniometer. The surface of the porcelain plate contained mainly crystallites of 3-quartz solid solution. As being far from the surface, the quantity of 3-quartz solid solution reduced rapidly, and the crystallites of indialite and enstatite increased. Crystallites of indialite and enstatite were distributed uniformly in the interior more than 200 um from the surface. It suggests a possibility of improvement in the capability against thermal shock by reducing the crystalline size and by homogenizing the crystallite distribution in the vicinity of the surface. In the case of two kinds of glass ceramics, almost the same X-ray microdiffraction (XRMD) patterns were obtained from any position of the plate. This indicates that random orientation and uniform distribution of their crystalline constituents, which explain their superior resistance against thermal shock.2. A brass sample holder with an exchangeable copper wire was made for XRMD analysis of small samples. An individual particle in airborne particulates, which was sorted under a microscope, was stuck with adhesive onto the wire tip of the holder, and analyzed by use of an X-ray microdiffractometer. It allowed to identify clearly a greater number of minor components in airborne particulate samples, and even a particle as small as about 0.03 ug. For example, ultramicro amounts of phlogopite and mullite were detected in Dukou's dust fall. It also indicated that Dukou dust fall contained magnetite of several different forms, i.e., as a major constituent in black grains and fragments, and as a minor constituent in reddish black aggregates and black spheres; So were hematite, calcite, and mullite.