[show abstract][hide abstract] ABSTRACT: The crystal structures of the synthesized superhard diamondlike BC <sub>5</sub> have been extensively explored through ab initio evolutionary algorithm. We uncovered seven intriguing low-energy structures all possessing sp<sup>3</sup> hybridizations. After examining the dynamical stability, it is found that two Pmma structures ( Pmma-1 and Pmma-2 ) are energetically more preferable. The simulated x-ray diffraction pattern, Raman modes, and Vickers hardness for Pmma-1 and Pmma-2 structures show remarkable agreement with the experimental data. Electronic and electron–phonon coupling calculations reveal that the two Pmma structures are hole conducting and superconducting with critical temperature ∼11–23 K .
Journal of Applied Physics 08/2010; · 2.21 Impact Factor