Molecular dynamics simulation and theoretical analysis of carbon diffusion in cementite

Characterization of single‐walled carbon nanotubes synthesized using iron and cobalt nanoparticles derived from self‐assembled diblock copolymer micelles

“…As a result, a high carbon concentration is required to initiate SWCNT growth. With the increase in carbon concentration, Fe 3 C is formed prior to carbon precipitation, which may slow down carbon diffusion, leading to lower growth rate 19, 20. This is consistent with our observation of shorter SWCNTs and higher carbon feed rate for iron nanoparticles.…”

Ferrite-to-Austenite and Austenite-to-Martensite Phase Transformations in the Vicinity of a Cementite Particle: A Molecular Dynamics Approach

“…Figure 1a) are provided in Refs. [39,40]. We constructed a ferrite-cementite and an austenite-cementite bicrystal, in which both phases occupy approximately the same space (see Figure 1b).…”

“…For the Fe-Fe interaction, we used Meyer-Entel interaction [12], which implements the bcc-fcc transition. To describe the Fe-C interaction, we used the pair potential developed by Johnson et al [47], as it was used in previous computational work on cementite [39,40]. As we demonstrated previously, the combination of the Meyer-Entel and the Johnson potential allows to model the α-γ phase transformation in dilute Fe-C alloys satisfactorily [48,49].…”

“…For the C-C interaction, we followed previous work on cementite modeling [39,40] and used the purely repulsive Born-Meyer potential [52],…”

“…We used the parameters A = 764.2 eV and r s = 0.219 Å with a cut-off radius of 1.5 Å as proposed in [53]; note that this cut-off is substantially smaller than the distance between the nearest-neighbor carbon atoms, 3.02 Å. Elmer and Levchenko [39,40] justified the use of a purely repulsive C-C potential by noting that, during the simulation, C atoms will never come closer to each other than the cut-off radius; we verified that this is the case also in our study.…”