Star shaped cyclic twinned nanowires

We report the discovery of a new class of nanowires with a star-shaped cross section. Unlike most nanowires, it shows a prominent regular reentrant surface profile. The electron diffraction and electron energy loss spectroscopy analyses indicate that the nanowire is composed of superhard boron suboxide (B6O). The fivefold symmetry of the star-shaped nanowire could be understood as a cyclic twinning structure. The crystallographic analysis further suggested that it could be a common occurrence in boron-rich compounds. Star-shaped nanowires with regular reentrant surfaces are attractive for applications in nanotechnology.