Structural investigations of a boron carbide nanorod with pseudo-fivefold twinned cross-section

In this article, a detailed investigation of the cross-section structure of a fivefold twinned boron carbide nanorod is presented. TEM observations reveal that the nanorod possesses a remarkable pseudo-fivefold twinned cross-section which consists of eight subcrystals packing around its fivefold axis. It is proposed that the negative angular mismatch of 5° for the unrelaxed boron carbide nanowires, which arises from the imperfectness of filling five twinned segments into a 360° solid space, is to be accommodated in one single subunit. The nanorod is found to be free from damage during sample preparation and it retains the intrinsic structural distortions of boron carbide nanowires.