Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Phys Rev Lett. 2012 Jul 20;109(3):035501. doi: 10.1103/PhysRevLett.109.035501. Epub 2012 Jul 16.
Twisted zinc oxide nanowires and nanotubes were recently synthesized by screw-dislocation growth. We show theoretically that once their diameter increases above a critical size of the order of a few atomic spacings, the existence of these structures can be rationalized in terms of the energetics of surfaces and veritable Eshelby's twist linear elasticity mechanics supplemented by a nonlinear core term. For Burgers vector larger than the minimum allowed one, a twisted nanotube with well-defined thickness, rather than a nanowire, is the most stable nanostructure. Results are assistive for designing ultrathin nanostructures made out of nonlayered materials.
最近通过螺旋位错生长合成了扭曲的氧化锌纳米线和纳米管。我们从理论上表明，一旦它们的直径增大到几个原子间距的临界尺寸以上，这些结构的存在就可以用表面能和真正的埃舍尔比扭转线性弹性力学来合理化，同时还需要补充一个非线性核心项。对于大于最小允许值的柏格斯矢量，具有明确定义厚度的扭曲纳米管而不是纳米线是最稳定的纳米结构。这些结果有助于设计由非层状材料制成的超薄纳米结构。
