New Mechanism for Graphene-to-Diamond Phase Transition

While both graphene and diamond belong to the elementary substance of carbon, their value is poles apart. Recently, Hebei University of Technology has made huge breakthroughs in graphene-diamond phase transition mechanism theory. Nature has published a dissertation titled "Mechanism for direct graphite-to-diamond phase transition". The first author is Xie Hongxian, a Doctor from Hebei University of Technology. The research has provided a new train of thought for synthetic diamond: polycrystalline synthetic diamond grain sizes and single crystalline synthetic diamond can be controlled by human will.

According to iAbrasive, diamond structure is cubic crystal, while graphene structure is an "ABABA" stratiform crystal. So if we need to transform graphene into diamond, the first thing that needs to be done is to transform graphene into an "ABCABCA" structure, then graphene will go through atomic plane bending to transform into cubic diamond. The research has come up with a new transitional mechanism by systematic molecule dynamics analog computation. The research indicates that if graphene interlamellar spacing is compressed to 0.24 nm along a 210 direction, single cubic diamond is done; if graphene interlamellar spacing is too big or too small, we may get polycrystalline cubic diamond or hexagonal-structure diamond, and grain sizes depend on graphene interlamellar spacing.