C-directional compression of nano-graphite: a comparison between effects of uniform and non-uniform pressure

✍ Scribed by Chunzhang Zhu; Wanlin Guo

• Book ID: 103888758
• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 365 KB
• Volume: 406
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2011.04.023

✦ Synopsis

The mechanism of phase transition and evolution in graphite under uniform compression and spherical nanoindentation along the c-direction is investigated through systematical molecular dynamics simulations. Under both the loading conditions, the soft graphite phase can sustain pressure up to 16-20 GPa, beyond which it transforms into a new phase characterized by a much higher stiffness. More and more interlayer bonds will be created in the new hard phase with the increase of the pressure until an unstable state is reached. The critical pressure to produce the quenchable hard phase with a permanent sp 3 bonding remaining after unloading is shown to be as high as $ 880 GPa under uniform compression, as opposed to only $ 75 GPa under nanoindentation. Therefore, application of nonuniform pressure is significantly more helpful for creating diamond-like sp 3 structures in graphite by cold-compressive technique.