2009.12.02

31A, Eigineering 2nd Bld, Hongo Campus

Prof. Stephan Irle

   Institue for Advanced Research, Nagoya University

Title: Quantum chemical molecular dynamics simulations of SWNT nucleation and growth on iron and nickel

Abstract:

Self-consistent-charge density-functional tight-binding molecular dynamics simulations of transition metal (Fe, Ni)-catalyzed nucleation and growth of single-walled carbon nanotubes (SWCNTs) were performed. Adding C atoms and C2 units to the initially bare metal particles, we observed the nucleation of carbon caps, and continued growth of short SWCNT fragments. Adding C2H2 on the bare particles, polyacetylene formation is dominant, and hydrogen is only slowly removed. Growth appears to be a 2-step process, i) disordered pentagon/hexagon growth at the carbon/metal interface, and ii) annealing to all-hexagons where the colder top-layered (n,m) chirality is imprinted on the newly forming network. The carbon-metal adhesion strength governs growth rates and mechanism: weaker C-M interaction favors more fullerene-like ring-collapse growth of longer polyyne chains.

Schedule: 15:00  ~ 16:30  Friday 2nd December, 2009

Place: 31A, Engineering 2nd Bld, Hongo Campus

Attached file:  34th open seminar.pdf