邻苯二甲酸氢铊单晶位错的Borrmann象衬度

本文报道新近开发的、X射线衍射效率很大的邻苯二甲酸氢铊(TAP)单晶中位错的Borrmann象。位错近核心区的精细象衬度不但与晶片的厚度有关,而且随着Borrmann系数ε值的下降而模糊,以至精细象结构随衬度反转而完全消失。关键词：

BORRMANN IMAGE OF DISLOCATION IN THE CRYSTAL OF THALLIUM ACID PHTHALATE

The crystal of thallium acid phthalate (TAP) is a newly developed X-rays analyzing ele-ment with higher diffraction power. The Bormann image of the spiral dislocations has been observed and studied by means of X-ray topography. It is shown that the image contrast with fine structure nearly in the core of dislocation is decreasing not only with decreasing the crystal thickness, but also with decreasing the Borrmann coefficient s so greatly as to blur or even to make the fine contrast information loss completely when the images are inversed from "white" to "black" in the contrast.