Entrapment of Inclusions in Diamond Crystals Grown from Fe-Ni-C System

Diamond single crystals grown from Fe-Ni-C system at high temperature-high pressure (HPHT) usually contain inclusions related to the metallic catalyst. During the diamond growth, the metallic inclusions are trapped by the growth front or are formed through reaction between the contaminants trapped in the diamond. In the present paper, the metallic inclusions related to the catalyst were systematically examined by transmission electron microscopy (TEM). The chemical composition and crystal structure of the metallic inclusions were for the first time determined by selected area electron diffraction pattern (SADP) combined with energy dispersive X-ray spectrometry (EDS). It is shown that the inclusions are mainly composed of orthorhombic FeSi2, fcc (FeNi)23C6, and orthorhombic Fe3C, hexagonal Ni3C.

人造金刚石晶体中微观杂质的TEM分析

本文成功地利用透射电子显微术探讨了高温高压条件下于Fe Ni C系统中生长的人造金刚石单晶内部的微观杂质。分析了金刚石晶体中杂质的微观结构、化学成分组成、晶体结构及其可能形成的原因。研究结果表明 ,金刚石晶体中微观杂质与原材料、传压介质和高温高压过程密切相关 ,主要由面心立方 (FeNi) 2 3C6 ,正交结构的FeSi2 ,面心立方SiC和非晶态石墨组成。