Design, synthesis, microstructure and electrical properties of thermal-strained PZT films

Abstract

Abstract The integration units with functional and structural material components have been developed largely recently. In the present study, 200 nm-thick polycrystalline PbZr0.52Ti0.48O3 (PZT) films with a dense columnar structure were grown on LaNiO3 (LNO) buffered heat-resistant steel substrates via a low-cost chemical solution approach. The behavior of the functional PZT films when combined with the structural steel was investigated mainly by TEM and electrical measurement. A large in-plane compressive stress was obtained in the PZT films due to the thermal expansion mismatch of about 88.2 % between the thin films and the steel substrates, which intensifies the orientation of the films toward c-axis. Sub-10 nm 90° nanodomains were alternately distributed in [001] grains which is beneficial to the piezoelectric performance, and the equivalent d33 value is ～44.4 pm V−1. A remnant polarization (Pr) of ～67.3μC/cm2 and a dielectric constant of ～425 were obtained. The enhanced electrical properties are associated with the stress-induced improved c-axis spontaneous polarization and crystal orientation in the hybrid system. This work may provide a theoretical basis for further integrating functional elements into metallic materials, which is valuable for covering the gap between academic research and industrial mass production.