Structural changes in graphite-to-diamond transition on the P-T link of minimum concentration jump in carbon

Abstract

Structural aspects of the direct graphite-diamond transition have been studied along with the reaction P-T-hysteresis arising during phase transformations in carbon. The direct transition has been found to be a high-molecular reaction of cross-linking of two-dimensional graphite networks resulting in their transformation into three-dinensions1 covalent networks of diamond. Crystal-oriented barochemical reaction of cross-linking is described by two fundamental matrices: the matrix of atomic coordinates transformation and the matrix of atomic concentration Jump. A method of hi&-molecular thermomechanics developed in this paper is used to discuss P-T-hysteresis that was experimentally observed in, the direct and inverse transitions in carbon.