Ordering effects in 2D hexagonal systems of binary and ternary C-B-N alloys

• Published in: Computational materials science 2018-05, Vol.147, p.115-123
• Main Authors: Jamróz, Agnieszka, Majewski, Jacek Adam
• Format: Article
• Language: English
• Subjects: Atomic scale structure; Composition fluctuations; Computer simulation; Disordered systems; Order-disorder effects
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2018.01.059

[Display omitted] •Graphene based substitutional alloys with boron and nitrogen were investigated.•Neither binary CN and CB alloys nor ternary CBN alloys are random.•CN, CB, and CBN alloys exhibit pronounced short-range order.•The mutual BB and NN bonds in binary alloys are energetically unfavourable.•In the CBN alloy, the h-BN domains form within the graphene lattice. We present theoretical study of ordering phenomena in binary C1-xBx,C1-xNx, and ternary C1-2xBxNx alloys forming two-dimensional, graphene-like systems. In order to find equilibrium distribution of different species corresponding to minima of the energy, we use Monte Carlo approach in Metropolis regime. We employ empirical Tersoff potential to account for the interactions between atoms and to calculate the total energy. We model alloys considering large systems containing up to 20 000 atoms with various N and B concentrations. For quantitative description of ordering phenomena in the studied alloys, we determine Warren-Cowley Short Range Order (SRO) parameters for the first coordination shell. Our studies clearly demonstrate the presence of the SRO in the studied alloys. Binary alloys are neither random nor the clustering of N (or B) dopants takes place. In the ternary alloys, the h-BN domains are formed within the carbon areas.