Magic Numbers in a One-Dimensional Nanosystem: ZnS Single-Walled Nanotubes

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• 作者：Norawit Krainara ; Jumras Limtrakul ; Francesc Illas ; Stefan T. Bromley
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：November 7, 2013
• 年：2013
• 卷：117
• 期：44
• 页码：22908-22914
• 全文大小：382K
• 年卷期：v.117,no.44(November 7, 2013)
• ISSN：1932-7455

文摘

The structure and stability of a range of zigzag (n,0) and armchair (n,n) ZnS SWNTs of increasing diameter are investigated theoretically using density functional theory. Zigzag and armchair SWNTs are found to be most energetically stable when considerably structurally reconstructed with respect to the corresponding metastable relatively smooth SWNTs. A strong relation between the average Zn鈥揝(Zn)鈥揨n dihedral angles in the SWNTs and their relative energetic stability points to the out-of-plane tendency of the highly polarizable S anions as the driving force behind the observed distortions. The internal energetic strain in reconstructed armchair ZnS SWNTs is found to gradually monotonically decrease toward that in a reconstructed single 2D ZnS sheet with increasing diameter. This tendency follows that in previously reported calculations for both armchair and zigzag SWNTs of C, BN, MoS₂, and TiO₂. For reconstructed zigzag ZnS SWNTs, however, the general decrease in energetic strain with increasing diameter possesses clear oscillations, with (3a,0) SWNTs possessing the highest stability and largest band gap. We compare this discrete pattern of stability with that often encountered for particularly stable nanoclusters possessing 鈥渕agic鈥?numbers of atoms. As far as we are aware, this is the first report of 鈥渕agic鈥?numbers being predicted to occur in a 1D nanosystem.