The elongated growth along the c-axis was because the
adsorption had more influence upon the growth rates of crystal
faces parallel to the c-axis than upon those crystal faces
perpendicular to the c-axis. The process of shape evolution
could be depicted in Fig. 5. At the beginning of mixing, plenty
of nuclei formed due to high supersaturation. When Tween80
adsorbed on the surfaces of the newly formed nuclei, the
growth of crystal faces parallel to the c-axis was relatively
retarded in comparison with that of crystal faces perpendicular
to the c-axis. Consequently, the rod-like crystals were elongated
along the c-axis.