Institute for Materials Science and Max Bergmann Center of Biomaterials, Dresden University of Technology, 01062 Dresden, Germany.
ACS Nano. 2011 Jun 28;5(6):4997-5005. doi: 10.1021/nn201099a. Epub 2011 May 5.
The transport properties, work functions, electronic structure, and structural stability of boron nanotubes with different lattice structures, radii, and chiralities are investigated theoretically. As the atomic structure of boron nanotubes and the related sheets is still under debate, three probable structural classes (nanotubes derived from the α-sheet, the buckled triangular sheet, and the distorted hexagonal sheet) are considered. For comparison with recent transport measurements [J. Mater. Chem. 2010, 20, 2197], the intrinsic conductance of ideal nanotubes with large diameters (D ≈ 10 nm) is determined. All considered boron nanotubes are highly conductive, irrespective of their lattice structures and chiralities, and they have higher conductivities than carbon nanotubes. Furthermore, the work functions of the three sheets and the corresponding large-diameter nanotubes are determined. It is found that the value of the nanotubes obtained from the α-sheet agrees well with the experiment. This indirectly shows that the atomic structure of boron nanotubes is related to the α-sheet. The structural stability of nanotubes with diameters > 2 nm approaches that of the corresponding boron sheets, and α-sheet nanotubes are the most stable ones. However, for smaller diameters the relative stabilities change significantly, and for diameters < 0.5 nm the most stable structures are zigzag nanotubes of the buckled triangular sheet. For structures related to the distorted hexagonal sheet the most stable nanotube is discovered to have a diameter of 0.39 nm.
理论研究了具有不同晶格结构、半径和手性的硼纳米管的输运性质、功函数、电子结构和结构稳定性。由于硼纳米管和相关片的原子结构仍存在争议，因此考虑了三种可能的结构类型（源自α-片的纳米管、褶皱三角形片和扭曲六边形片）。为了与最近的输运测量结果[J. Mater. Chem. 2010, 20, 2197]进行比较，确定了具有大直径（D ≈ 10nm）的理想纳米管的本征电导率。所有考虑的硼纳米管都是高导电的，与它们的晶格结构和手性无关，并且它们的电导率比碳纳米管高。此外，还确定了三种片和相应大直径纳米管的功函数。发现从α-片获得的纳米管的值与实验吻合得很好。这间接表明硼纳米管的原子结构与α-片有关。直径>2nm 的纳米管的结构稳定性接近相应的硼片，α-片纳米管是最稳定的。然而，对于较小的直径，相对稳定性会发生显著变化，对于直径<0.5nm 的情况，最稳定的结构是褶皱三角形片的锯齿形纳米管。对于与扭曲六边形片相关的结构，发现最稳定的纳米管的直径为 0.39nm。
