English

Thermomechanical properties of a single hexagonal boron nitride sheet

Mesoscale and Nanoscale Physics 2015-06-15 v1 Materials Science

Abstract

Using atomistic simulations we investigate the thermodynamical properties of a single atomic layer of hexagonal boron nitride (h-BN). The thermal induced ripples, heat capacity, and thermal lattice expansion of large scale h-BN sheets are determined and compared to those found for graphene (GE) for temperatures up to 1000 K. By analyzing the mean square height fluctuations <h2>< h^2> and the height-height correlation function H(q)H(q) we found that the h-BN sheet is a less stiff material as compared to graphene. The bending rigidity of h-BN: i) is about 16% smaller than the one of GE at room temperature (300 K), and ii) increases with temperature as in GE. The difference in stiffness between h-BN and GE results in unequal responses to external uniaxial and shear stress and different buckling transitions. In contrast to a GE sheet, the buckling transition of a h-BN sheet depends strongly on the direction of the applied compression. The molar heat capacity, thermal expansion coefficient and the Gruneisen parameter are estimated to be 25.2 J\,mol1^{-1}\,K1^{-1}, 7.2×106\times10^{-6}K1^{-1} and 0.89, respectively.

Keywords

Cite

@article{arxiv.1304.5972,
  title  = {Thermomechanical properties of a single hexagonal boron nitride sheet},
  author = {Sandeep Kumar Singh and M. Neek-Amal and S. Costamagna and F. M. Peeters},
  journal= {arXiv preprint arXiv:1304.5972},
  year   = {2015}
}