Asymmetric twinning crystals of Zinc oxide formed in a hydrothermal process

Abstract

AbstractWell crystallized ZnO powders with various morphologies such as hour glass‐shaped, shortened prismatic, flake‐like and prismatic form have been synthesized by adopting the system of Zn(Ac)2‐KOH‐H2O via a hydrothermal process at 200 °C for 2 h. It was found that the as‐synthesized hour glass‐shaped ZnO crystallites are asymmetric both in shape and stoichiometry: while the atomic ratio of O/(Zn+O) at the bigger end ranges from about 60% to 40% along the polar axis of the hour glass‐shaped ZnO crystallites, the atomic ratio of O/(Zn+O) at the smaller end remains almost constant at approximately 50%.