Analysis of Interfacial Phase between Substrates and Lead Zirconate Titanate Thin Films Synthesized by Hydrothermal Method

Abstract

Hydrothermal synthesis of lead zirconate titanate (PZT) films was achieved using two sequential processes. The first step is the reaction of the substrate with a solution, which is called the “nucleation process”, and the second step is the “crystal growth process”. Variation in the morphology of final products was produced by changing the duration of the nucleation process. At least 12 h of the nucleation process was required to obtain a PZT film. A duration over 12 h in the nucleation process resulted in thicker PZT film and larger displacement of the bending actuator fabricated using such a film. These findings can be explained by assuming the existence of an interfacial phase between the Ti substrate and PZT film, the piezoelectric constant of which would be lower than that of the PZT film. Energy dispersive X-ray spectrometry (EDX) analyses provide evidence to support the assumption that the interfacial phase is Ti-rich PZT.