A ternary phase diagram for amorphous carbon

The sp2 phase in amorphous carbon is modeled as coexisting nc-graphite, fused aromatic ring, and olefinic chain clusters. A phenomenological linear dispersion model is derived to calculate the G peak position from weighted relative contents of the sp2 clusters and vice versa. Ternary phase diagrams based on the weighted relative contents provide quantitative predictions for G peak position, dispersion rate, sp3 content, H content, and other properties of amorphous carbon. The phase diagrams are used to classify and characterize amorphous carbon, and to track their structural changes due to modification procedures like annealing, doping, and ion irradiation. Numerous insights are drawn from patterns in the distributions or in the migration paths of the analyzed samples.