Hexagon-Islands Density and Size Distribution on Growing Single-Walled Carbon Nanotubes in the Kinetic 5-Vertex Model  

作　　者：Sènan Ida Valérie Hontinfinde Josaphat Adda Joel Kple Franck Zounmenou Félix Hontinfinde Sènan Ida Valérie Hontinfinde;Josaphat Adda;Joel Kple;Franck Zounmenou;Félix Hontinfinde(ENSGMM, Universit dAbomey (UNSTIM), Abomey, Bnin;Dpartement de Physique, Universit dAbomey-Calavi, Abomey-Calavi, Benin;IMSP, Universit dAbomey-Calavi (UAC), Dangbo, Bnin)

机构地区：[1]ENSGMM, Universit dAbomey (UNSTIM), Abomey, Bnin [2]Dpartement de Physique, Universit dAbomey-Calavi, Abomey-Calavi, Benin [3]IMSP, Universit dAbomey-Calavi (UAC), Dangbo, Bnin

出　　处：《World Journal of Condensed Matter Physics》2024年第4期77-95,共19页凝固态物理国际期刊（英文）

摘　　要：A kinetic 5-vertex model is used to investigate hexagon-islands formation on growing single-walled carbon nanotubes (SWCNT). In the model, carbon atoms adsorption and migration processes on the SWCNT edge are considered. These two dynamic processes are assumed to be mutually independent as well as mutually dependent as far as the whole growth of the nanotube is concerned. Key physical parameters of the model are the growth time t, the diffusion length Γ defined as the ratio of the diffusion rate D to the carbon atomic flux F and the SWCNT chiral angle. The kinetic equation that describes the nanotube edge dynamics is solved using kinetic Monte Carlo simulations with the Bortz, Kalos and Lebowitz update algorithm. The behaviors of islands density and size distribution are investigated within the growth parameters’ space. Our study revealed key mechanisms that enable the formation of a new ring of hexagons at the SWCNT edge. The growth occurs either by pre-existing steps propagation or by hexagon-islands growth and coalescence on terraces located between dislocation steps, depending on values of model parameters. This should offer a road map for edge design in nanotubes production. We also found that in appropriate growth conditions, the islands density follows Gaussian and generalized Wigner distributions whereas their size distribution at a given growth time shows a decreasing exponential trend.A kinetic 5-vertex model is used to investigate hexagon-islands formation on growing single-walled carbon nanotubes (SWCNT). In the model, carbon atoms adsorption and migration processes on the SWCNT edge are considered. These two dynamic processes are assumed to be mutually independent as well as mutually dependent as far as the whole growth of the nanotube is concerned. Key physical parameters of the model are the growth time t, the diffusion length Γ defined as the ratio of the diffusion rate D to the carbon atomic flux F and the SWCNT chiral angle. The kinetic equation that describes the nanotube edge dynamics is solved using kinetic Monte Carlo simulations with the Bortz, Kalos and Lebowitz update algorithm. The behaviors of islands density and size distribution are investigated within the growth parameters’ space. Our study revealed key mechanisms that enable the formation of a new ring of hexagons at the SWCNT edge. The growth occurs either by pre-existing steps propagation or by hexagon-islands growth and coalescence on terraces located between dislocation steps, depending on values of model parameters. This should offer a road map for edge design in nanotubes production. We also found that in appropriate growth conditions, the islands density follows Gaussian and generalized Wigner distributions whereas their size distribution at a given growth time shows a decreasing exponential trend.

关 键 词：Kinetic 5-Vertex Model Single-Walled Carbon Nanotube Monte Carlo Simulations Island Density and Size Distribution Gaussian and Wigner Distributions 

分 类 号：TB3[一般工业技术—材料科学与工程]