Hence, the lateral faces of the rods correspond
to six equivalent prismatic planes. The lateral growth of the protrusions
and their evolution to form nanoplates seems to be related
to the incorporation of dopants during the thermal treatments.
The secondary growth has not been observed in undoped ZnO
structures obtained by similar methods [15], while we have found
hexagonal nanoplate stacks in Sn [11,12] and Eu [14] doped ZnO
structures.