Tailoring nanomechanical properties of hard and soft PZT piezoceramics via domain engineering by selective annealing

Abstract

The nanomechanical properties of polycrystalline “hard” and “soft” lead zirconate titanate (PZT) (abbreviated as PZT-H and PZT-S, respectively) are measured on samples having different ferroelectric domain configurations. The ferroelectric domain configurations are varied by selectively annealing the as poled samples below and above the curie temperature, Tc. The ferroelectric domain configurations characterized using piezoresponse force microscopy reveal that the degree of randomization of ferroelectric domains increases with increasing annealing temperature. Nanoindentation experiments reveal that the above Tc annealed samples exhibit the highest hardness, H among all the samples. All the samples, exhibit strong indentation size effect where H decreases with increasing in indentation load. The possible reasons for enhancement in Hin annealed samples is attributed to the differences in ferroelectric domain configurations, defect dipoles, and oxygen vacancies. The results provide insights about designing piezoelectric materials with good combination of mechanical and piezoelectric properties. © 2021 Elsevier Ltd