Robust Dirac-Cone Band Structure in the Molecular Kagome Compound (EDT-TTF-CONH2)6[Re6Se8(CN)6]

详细信息    查看全文

• 作者：Sandra Carlsson ; Leokadiya Zorina ; David R. Allan ; J. Paul Attfield ; Enric Canadell ; Patrick Batail
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：March 18, 2013
• 年：2013
• 卷：52
• 期：6
• 页码：3326-3333
• 全文大小：478K
• 年卷期：v.52,no.6(March 18, 2013)
• ISSN：1520-510X

文摘

(EDT-TTF-CONH₂)₆[Re₆Se₈(CN)₆] is a molecular solid with R3̅ space group symmetry and has the remarkable feature of exhibiting hybrid donor layers with a kagome topology which sustain metallic conductivity. We report a detailed study of the structural evolution of the system as a function of temperature and pressure. This rhombohedral phase is maintained on cooling down to 220 K or up to 0.7 GPa pressure, beyond which a symmetry-breaking transition to a triclinic P1̅ phase drives a metal to insulator transition. Band structures calculated from the structural data lead to a clear description of the effects of temperature and pressure on the structural and electronic properties of this system. Linear energy dispersion is calculated at the zero-gap Fermi level where valence and conduction bands touch for the rhombohedral phase. (EDT-TTF-CONH₂)₆[Re₆Se₈(CN)₆] thus exhibits a regular (right circular) Dirac-cone like that of graphene at the Fermi level, which has not been reported previously in a molecular solid. The Dirac-cone is robust over the stability region of the rhombohedral phase, and may result in exotic electronic transport and optical properties.