Radiation-Induced Transformation of Graphite to Diamond

Abstract

It is demonstrated theoretically that particle irradiation may lead to a destabilization of graphitic structures with respect to low-pressure growth of diamond. This is due to the large difference in the cross sections for irradiation-induced displacements of carbon atoms in diamond and graphite. A nonequilibrium phase diagram is calculated that shows the stability of graphite and diamond as a function of the displacement rate of atoms. The theoretical results are related to the experimentally observed transformation of spherical graphitic onions to diamond under electron irradiation.