Fine structure analysis of spherical carbon particles produced in a methane plasma

摘要

We have investigated the growth mechanism as well as the structure of spherical carbon particles grown to micron sizes in a low pressure columnar CH_4/H_2 plasma by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). From SEM observations, we found a fact that the spherical carbon particles were formed not on the substrate surface but in the sheath. From TEM observations, it was clarified that the spherical carbon particles were composed of graphite onions ranging from 2 to 10 nm and diamonds of ca. 5 nm were growing at the same time.