with different crystal growth rate.
Firstly, Bi and Te atoms were sputtered and deposited on the
surface of substrate. Then, nucleation began and hexagonal islands
formed due to the anisotropic diffusion. Usually, for Bi2Te3 material,
the preferential growth of (0 1 5) crystal plane is easy to form
hexagonal flakes, while the preferential growth of (0 0 l) and (0 1 5)
crystal planes result in the formation of rods with oriented layer
rather than that of hexagonal flakes