Molecular dynamics study on the mechanical properties of carbon doped single-layer polycrystalline boron-nitride nanosheets

In this paper, we study the mechanical behavior of carbon doped polycrystalline boron-nitride under uniaxial loading conditions by Molecular Dynamic (MD) simulations. We determine the influence of doping, grain size and temperature. Therefore, samples of polycrystalline (h-BN) with equivalent grain sizes ranging from 1 to 10 nm are generated, and the effect of doping with concentration of carbon atoms ranging from 1% to 15% on these nanaosheets at room temperature is quantified subsequently. Furthermore, samples with 3% and 6% carbon doping were fabricated and equivalent grain sizes ranging from 1 to 10 nm at room temperature is considered. In the end, we subject the fabricated samples to uniaxial loading in temperatures ranges between 100 and 900 K. Our findings revealed that by substitution of boron and nitrogen atoms with carbon (up to 8%), the ultimate tensile strength and corresponding failure strain of carbon doped polycrystalline h-BN increase. Increasing the grain size in carbon doped polycrystalline h-BN, the ultimate tensile strength increases whereas the failure strain decreases. Although the temperature increment has a negative influence on the mechanical properties of carbon doped polycrystalline h-BN, it still yields excellent mechanical properties, with the ultimate tensile strength of 100-120 GPa at 900 K.