Hydrothermal deposition of heteroepitaxial lead zirconate titanate nanostructures and thin films

This paper describes the hydrothermal growth of heteroepitaxial PZT nanostructures on single-crystal, SrTiO₃ substrates. Short processing times of 30 min led to the nucleation and growth of sporadic, cubic nanoscale PZT islands on the surface of the substrate. In some cases, individual islands coalesced in one direction to form microwires over 1 mm in length. Imperfections in the surface of the substrate introduced during polishing were thought to be responsible for the preferential nucleation. Longer reaction times up to 24 h resulted in the formation of heteroepitaxial PZT films, up to a micron in thickness, that were highly (1 0 0)-oriented. Piezoresponse force microscopy conducted on isolated islands and microwires, grown on conductive Nb:SrTiO₃ substrates, gave an indication that the structures were piezoelectric.