In-situ electron microscopic study of the surface transition from nanodiamond to onion like carbon
The surface structural transformation to onion-like graphite carbon has significantly affected the performance of nanodiamond.However,the inevitable amorphous carbon layer on the surface of nanodiamond is usually ignored.In this work,pure nanodiamond particles without surface amorphous carbon layer were obtained by electron beam irradiation and in situ thermal oxidation based on in situ ambient spherical aberration electron microscopy.The result showed that onion like carbon was easier to be formed when there existed amorphous carbon layer on the surface of nanodiamond.In contrast,onion like carbon was relatively difficult to be formed from the nanodiamond with good surface crystallinity and no amorphous carbon layer.In addition,nanodiamonds were completely transformed into the onion carbon structure at a lower temperature and in a shorter time by the synergetic effect of electron beam irradiation and high temperature heating.The result here provide a deep understanding of the inhibition of the surface graphitization transformation of nanodiamond,and also provide a method for the transformation from nanodiamond to onion like carbon structure.
nanodiamondamorphous carbononion like carbonsurface structure transformation
万方数据
维普
