<< Many substances with different chemical and physical properties, from diamonds to graphite, are made up of carbon atoms. Amorphous forms of solid carbon do not have a fixed crystal structure and consist of structural units—nanosized graphene particles. >>
(AA) << studied the structure of amorphous carbon and suggested classifying it as a separate type of amorphous solid bodies: a molecular amorphic with enforced fragmentation. (..) sp2 amorphous carbon is a fractal structure based on nanosized graphene domains that are surrounded by atoms of other elements (hydrogen, oxygen, nitrogen, sulfur, and so on). >>
<< The discovery and experimental confirmation of the graphene nature of the 'black gold' will completely change the theory, modeling, and interpretation of experiments with this class of substances. However, some questions remain unanswered. What does solid-state physics make of this amorphous state of solid carbon? What role does amorphous carbon with sp2-hybridization play in the bigger picture? >> Elena Sheka.
Physicists describe a new type of amorphous solid bodies. RUDN University. Dec 03, 2020.
E. F. Sheka ,Ye. A. Golubev, N. A. Popova. Amorphous state of sp2 solid carbon. Fullerenes, Nanotubes and Carbon Nanostructures. doi: 10.1080/ 1536383X.2020.1815713. Sep 03, 2020.
Also
word 'allotropy' in Cambridge Dictionary
