Properties of discrete breathers in graphane from ab initio simulations

Article

关键词: REVERSIBLE HYDROGENATION;    MOLECULAR-DYNAMICS;    NONLINEAR LATTICES;    CARBON MATERIALS;    LOCALIZED MODES;    GRAPHENE;    PSEUDOPOTENTIALS;    GENERATION;    CRYSTALS;    SOLITONS;   

DOI  :  10.1103/PhysRevB.90.045432

来源: SCIE

【 摘 要 】

A density functional theory (DFT) study of the discrete breathers (DBs) in graphane (fully hydrogenated graphene) was performed. To the best of our knowledge, this is the first demonstration of the existence of DBs in a crystalline body from the first-principle simulations. It is found that the DB is a robust, highly localized vibrational mode with one hydrogen atom oscillating with a large amplitude along the direction normal to the graphane plane with all neighboring atoms having much smaller vibration amplitudes. DB frequency decreases with increase in its amplitude, and it can take any value within the phonon gap and can even enter the low-frequency phonon band. The concept of DB is then used to propose an explanation to the recent experimental results on the nontrivial kinetics of graphane dehydrogenation at elevated temperatures.

【 授权许可】

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