Point Defects and Self-Diffusion in Graphite

Transport Gap Opening and High On–Off Current Ratio in Trilayer Graphene with Self-Aligned Nanodomain Boundaries

“…In our trilayer graphene on vicinal SiC, defects and interstitials may exist, which may be frozen under 100 K and migrate at higher temperatures (100À300 K). 44 The mobility of such interstitial defects could be responsible for the disappearance of the transport gap at temperatures above 100 K (Figure 6). Another possible origin of the transport gap observed in trilayer graphene on vicinal SiC(001) at temperatures below 150 K could be related to mechanical strain applied to the graphene nanoribbons during the sample cooling.…”

Sublimation Kinetics for Individual Graphite and Graphene Nanoparticles (NPs): NP-to-NP Variations and Evolving Structure-Kinetics and Structure-Emissivity Relationships

“…An obvious question is the extent to which annealing is important during sublimation, i.e., is annealing fast enough to significantly modify the surface site distribution, as it evolves during sublimation? The E a for lateral diffusion of C atoms within perfect basal planes is estimated to be in the ~675 to 780 kJ/mol range, 28 and annealing of dislocation loops by a vacancy creation/migration mechanism has E a ~800 kJ/mol, 47 both substantially higher than the E a s for NP sublimation. As already noted, interconversion between different edge structures should be fast, however, that simply converts between different types of under-coordinated sites with similar energies, rather than reducing their numbers.…”

“…The net energy to remove an atom from a perfect basal plane, creating a mono-vacancy, is reported to be in the 705 to 725 kJ/mol range, [27][28][29][30][31][32][33][34] and removing C 2 to create a di-vacancy has net formation energy estimated to be in the 700 -790 kJ/mol range. [33][34][35] It is likely that the E a s for these processes are higher yet, thus, under our conditions, sublimation of C or C 2 from perfect basal plane sites should make only minor contributions to the total rate.…”

Modelling defect evolution in irradiated graphite

“…MD shows that both transformations are possible and that the resulting structures are quite stable. The direct transformation from a perfect graphite structure to the 5577 system was originally proposed by Dienes [36] and Thrower [38] as a means by which diffusion in graphite could take place. It is sometimes also called a Stone-Wales [39] transformation.…”