First Order Structural Phase Transition in ZnO Nanostructures at High Pressure

This paper reports the results of a theoretical investigation on the compress ional behavior of ZnO nanostructures like ZnO-nanowire, ZnO-nanotube and ZnO-nanorods at high pressure during transformation from wurtzite to rock salt structure. A simple theory is proposed to predict the transition pressure (PT) of these nanomaterials, which gets support from the Mie-Gruneisen theory of thermal expansivity as formulated by Born and Huang. We have considered the Tait's equation of state to study the effect of pressure on the phase transition from wurtzite (W) to rock salt (R) phase in three nanostructures of zinc oxide material. The results obtained are found to present a good agreement with the available experimental data as well as other formulations. A good agreement between theoretical and experimental results demonstrates the validity of the equation of state used in the present study to explain the structural behavior of nanomaterials at high pressure.