Electrostatic force microscopy of as-grown (0Â 0Â 1)-oriented Pb(Zr,Ti)O3 nanolayers

Highly (0 0 1)-oriented ferroelectric PbZr0.53Ti0.47O3 nanolayers are prepared by a sol-gel method on conducting LaNiO3 electrodes with SiO2/Si(1 0 0). Ferroelectric domains in the layers are observed using atomic force microscopy, registering the electrostatic force response of the layers in the presence of a low AC field. Surface morphology and domains in the layers are observed using atomic force microscopy with the lock-in amplification technique. We observe a direct correlation between domain configurations and microstructural features in the as-grown nanolayers. Protruded grains show upward polarization, while most of the flat grains display downward polarization, suggesting that overall output of the as-grown polarization might be biased. Switching behavior of the layers reveals a significant asymmetric pattern, which is dependent on the voltage polarity and the original domain structure of the individual grains. This observation is attributed to preference of polarization states of each grain, indicating that local switching behavior is macroscopically expressed as an imprint phenomena.