Physical properties of a novel phase of boron nitride and its potential applications

A novel phase of boron nitride m-BN is proposed in this work. The elastic anisotropy, structural properties, mechanical properties and electronic properties of m-BN are investigated. First, m-BN is a wide and indirect band-gap semiconductor material, and the Fermi level and band gap are not sensitive to the effect of pressure. The bulk modulus of m-BN is 329 GPa, which is smaller than that of Pbca-BN and c-BN, but the Young's modulus and shear modulus of m-BN are greater than that of Pbca-BN. In addition, m-BN exhibits elastic anisotropy in bulk modulus, shear modulus, and Young's modulus. Almost all the ratios of the maximum and minimum values of Young's modulus and shear modulus for m-BN increase with increasing pressure. In addition, the elastic anisotropy of m-BN in the anisotropy of the bulk modulus along the alpha-axis A(Ba) and A(1) and A(3) (shear anisotmpic factors) increases with increasing pressure, while the anisotropy of m-BN in the bulk modulus along the alpha-axis A(Ba) and A(2) (shear anisotropic factor) decreases with increasing pressure.