Graphitization of diamond by ion impact: Fundamentals and applications

The fact that diamond may be transformed into graphite when a sufficient (critical) number of its bonds are broken as a result of ion-implantation related damage is used to learn about the nature and shape of the damage within each damage cascade. The changes in electrical conductivity following both Xe and C ion-implantations at different temperatures (150-690 K) are investigated. The data are analyzed in terms of a model which assumes that each ion leaves in its wake conducting (graphitic) spheres, the radii of which depend on implantation temperature. The radii decrease with increasing implantation temperature, T-i, due to dynamic annealing, until for T-i > 815 K the damage introduced by the passage of the ions is instantaneously annealed and no identifiable damage region is left behind. Applications which take advantage of the electrical and chemical properties of ion beam modified diamond are briefly discussed.