Semi-Metallic Be5C2 Monolayer Global Minimum with Quasi-Planar Pentacoordinate Carbons and Negative Poissons Ratio (Open Access Publisher's Version)
Journal Article - Open Access
NANJING NORMAL UNIV (CHINA) NANJING China
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Designing new materials with novel topological properties and reduced dimensionality is always desirable for material innovation. Here we report the design of a two-dimensional material, namely Be5C2 monolayer on the basis of density functional theory computations. InBe5C2 monolayer, each carbon atom binds with five beryllium atoms in almost the same plane, forming a quasi-planar pentacoordinate carbon moiety. Be5C2 monolayer appears to have good stability as revealed by its moderate cohesive energy, positive phonon modes and high melting point. It is the lowest-energy structure with the Be5C2 stoichiometry in two-dimensional space and therefore holds some promise to be realized experimentally. Be5C2 monolayer is a gapless semiconductor with a Dirac-like point in the band structure and also has an unusual negative Poissons ratio. If synthesized, Be5C2 monolayer may find applications in electronics and mechanics.
- Physical Chemistry