Quantum electronic mechanisms of atomic rearrangements during growth of hard carbon films

Considering that diamond can grow without combination of pressure and heat, other effects in addition to ion impact thermal spikes effects must exist, which are ruling the growth of diamond and ta-C films (tetrahedral amorphous carbon). A newly proposed quantum electronic activation model for the diamond and diamond-like atomic rearrangement of carbon atoms appears to be confirmed by various elder and more recently published experimental results. It is based on various types of effects producing activation energy, before producing heat. Thus, it is possible to excite electron–hole pairs, which during their diffusion produce some transversal transient polarization, which under specific conditions can result in a new metastable atomic structure. This article focuses on published work on atomic rearrangements, which have been observed during annealing of diamond and some kinds of DLC (diamond-like carbon) coatings, such as a-C:H and a-CNx coatings. These atomic rearrangements were explained by using essentially Raman spectroscopy results, which are reviewed in this article, before being discussed with additional new proposed aspects on fundamentals to consider and which have been up dated in their interpretation. The considered atomic rearrangement model appears then also to be in agreement with some formerly discussed catalytic effects, which under specific conditions, favorize the growth of diamond and more diamond-like carbon films. It is expected that this new quantum electronic atomic rearrangement model will not be limited only to diamond, ta-C and DLC materials.