The peculiar feature of forming different kinds of chemical bonds so called hybridizations, enables carbon to facilitate the amazing complexity of life. Miguel Caro from Aalto University and colleagues are now able to distinguish occurring chemical behavior of carbon atoms in amorphous form that has been known from measurements for a while without a satisfying explanation. This provides a microscopic picture of the emerging physical and chemical processes as well as allows material design made of thin films of carbon such as biologically implantable microelectronics.
Computational modeling using interatomic potentials may become very time consuming depending on the simulated system-size and the accuracy level of the calculations. The researchers attempt of simulating the “large-enough” box of carbon atoms is successful owing to a previously developed1 computationally efficient model having interatomic potentials generated by a machine-learning algorithm. Simulation results leads to a new mechanism of the surface construction and diamond like bulk formation: The peening mechanism as called by the authors, suggests that the pressure waves generated by the impacting ions creates a depletion region, is essentially different than the consensus of packing of atoms in a region of small volume. Around the impact site, the displaced carbon atoms induces a transformation of hybridization such that a diamond-like structure is formed within the bulk region below the surface.
The growth model is promising in optimizing diamond-like thin film growth as well as highlighting the role of machine learning in materials modeling.