Figure 5
Determining the direction of preferential nanotrack growth.
(a) Polarised micro-Raman backscattering LO phonon polar plots measured from pure a (001) GaAs crystal surface and the (001) GaAsBi surface. Below the plots are the corresponding possible basis directions (either [110] or 
) deduced from the analysis of the (001) GaAs polar data and the preferential nanotracks growth direction, measured with respect to (WRT) the GaAsBi polar plot. (b) Geometric information of relevant crystal faces relative to the [001] growth direction and (c) a schematic illustration of two simultaneous [111]B growth planes accommodated by the liquid interface, which evolves ultimately into movement in a single planar direction. A “crawling” mode then propagates with in-plane velocity v|| in the ±
bi-direction, with the liquid droplet pinned on nanotrack top by surface tension.
