Viscous state effect on the activity of Fe nanocatalysts.
Many applications of nanotubes and nanowires require controlled bottom-up engineering of these nanostructures. In catalytic chemical vapor deposition, the thermo-kinetic state of the nanocatalysts near the melting point is one of the factors ruling the morphology of the grown structures. We present theoretical and experimental evidence of a viscous state for nanoparticles near their melting point. The state exists over a temperature range scaling inversely with the catalyst size, resulting in enhanced self-diffusion and fluidity across the solid-liquid transformation. The overall effect of this phenomenon on the growth of nanotubes is that, for a given temperature, smaller nanoparticles have a larger reaction rate than larger catalysts.
Department of Engineering, University of Cambridge, Cambridge, U.K.
Felipe
F
Cervantes-Sodi
Thomas P
TP
McNicholas
Jay G
JG
Simmons
Jie
J
Liu
Gabor
G
Csányi
Andrea C
AC
Ferrari
Stefano
S
Curtarolo