Tetragonal Allotrope of Group 14 Elements
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- 作者：Zhisheng Zhao ; Fei Tian ; Xiao Dong ; Quan Li ; Qianqian Wang ; Hui Wang ; Xin Zhong ; Bo Xu ; Dongli Yu ; Julong He ; Hui-Tian Wang ; Yanming Ma ; Yongjun Tian
- 刊名：The Journal of the American Chemical Society
- 出版年：2012
- 出版时间：August 1, 2012
- 年：2012
- 卷：134
- 期：30
- 页码：12362-12365
- 全文大小：266K
- 年卷期：v.134,no.30(August 1, 2012)
- ISSN：1520-5126
文摘
Group 14 elements (C, Si, and Ge) exist as various stable and metastable allotropes, some of which have been widely applied in industry. The discovery of new allotropes of these elements has long attracted considerable attention; however, the search is far from complete. Here we computationally discovered a tetragonal allotrope (12 atoms/cell, named T12) commonly found in C, Si, and Ge through a particle swarm structural search. The T12 structure employs sp3 bonding and contains extended helical six-membered rings interconnected by pairs of five- and seven-membered rings. This arrangement results in favorable thermodynamic conditions compared with most other experimentally or theoretically known sp3 species of group 14 elements. The T12 polymorph naturally accounts for the experimental d spacings and Raman spectra of synthesized metastable Ge and Si-XIII phases with long-puzzling unknown structures, respectively. We rationalized an alternative experimental route for the synthesis of the T12 phase via decompression from the high-pressure Si- or Ge-II phase.