Structure, elastic, and electronic properties of the Nb2SnC1-xBx phases MAX: Ab initio calculations

The crystal structure, elastic, and electronic properties of the Nb2SnC1-xBx phases were investigated using first principles calculations within the local density approximation. We found that the substitution of carbon by boron atoms induces an increase in the lattice parameters, and therefore, the unit cell volume increases. On the other hand, elastic constants (except C-12) and hardness tend to increase as boron content increases. Thus, according to Born, Poisson's ratio, and Pugh's criterion, the Nb2SnC1-xBx phases are structurally stable, metallic, and show ductile behavio. The Phonon density of states of the Nb2SnC to Nb2SnB compounds showed no imaginary phonon frequency in the entire Brillouin zone; therefore, the P6(3)/mmc space group is dynamically stable. Furthermore, the density of states at the Fermi energy increases due to the increase of the B 2p states.

Automated summary

The crystal structure, elastic, and electronic properties of Nb2SnC1-xBx phases were investigated, showing that the substitution of carbon by boron atoms results in increased lattice parameters and unit cell volume. Additionally, as boron content increases, elastic constants (except C-12) and hardness tend to increase. The Nb2SnC1-xBx phases were found to be structurally stable, metallic, and exhibit ductile behavior according to various criteria.