Unraveling the structural transition mechanism of room-temperature compressed graphite carbon

The discovery of graphite transition to transparent and superhard carbons under room-temperature compression (Takehiko, et al. , Science , 1991, 252 , 1542 and Mao, et al. , Science , 2003, 302 , 425) launched decades of intensive research into carbon's structural polymorphism and relative phas...

Full description

Saved in:
Bibliographic Details
Published in:Physical chemistry chemical physics : PCCP 2021-09, Vol.23 (36), p.256-2566
Main Authors: Zhu, Sheng-cai, Hu, Qing-yang
Format: Article
Language:English
Subjects:
Allotropy
Atomic structure
Carbon
Crystal structure
Graphite
Phase transitions
Polymorphism
Room temperature
Sampling methods
Shearing
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The discovery of graphite transition to transparent and superhard carbons under room-temperature compression (Takehiko, et al. , Science , 1991, 252 , 1542 and Mao, et al. , Science , 2003, 302 , 425) launched decades of intensive research into carbon's structural polymorphism and relative phase transition mechanisms. Although many possible carbon allotropes have been proposed, experimental observations and their transition mechanisms are far from conclusive. Three longstanding issues are: (i) the speculative structures inferred by amorphous-like XRD peaks, (ii) sp 2 and sp 3 bonding mixing, and (iii) the controversies of transition reversibility. Here, by utilizing the stochastic surface walking method for unbiased pathway sampling, we resolve the possible atomic structure and the lowest energy pathways between multiple carbon allotropes under high pressure. We found that a new transition pathway, through which graphite transits to a highly disordered phase by shearing the boat architecture line atoms out of the graphite (001) plane upward or downward featuring without the nuclei core, is the most favorable. This transition pathway facilitates the generation of a variety of equally favorable carbon structures that are controlled by the local strain and crystal orientation, resembling structural disordering. Our results may help to understand the nature of graphite under room temperature compression. We resolve the transition pathway of compressed graphite, whose complex high-pressure structure is formed by shearing the boat architecture without nuclei core and controlled by local strain and crystal orientation.
ISSN:1463-9076
1463-9084
DOI:10.1039/d1cp03415d