Ferroelectric domain structures of 0.4-μm-thick Pb(Zr,Ti)O3 films prepared by polyvinylpyrrolidone-assisted Sol-Gel method

Strain imaging of piezoelectric material enables us to observe piezo/ferroelectric properties with high resolution. We observed single-step-deposited 0.4-mu m-thick Pb(Zr0.53Ti0.47)O-3 (PZT). The PZT film had the small granular grains in size with around 40 nm, while the rosettes were around several micrometers in diameter. Observed domain structures were only determined by the rosette structures formed by nucleation of PZT. The grains were not columnar but granular, and so there are many grains in thickness direction but they were (001)-oriented. Therefore, polarization was aligned normal to the surface, and the structure to determine domain boundaries is neither grain boundaries nor crystalline axes but rosette boundaries. Relatively thick films provided stable polarization. The domain structures are flexible and well controllable by external electric fields. The positive surface charges were generated in the PZT surface by negative tip voltages. The presented images suggest that the positive surface charges coupled with spontaneous polarizations were rich at the circumferences of the rosettes. The positive surface charges generated negative charges on the tip, and the negative charges were deposited on the sample surface from the scanned tip. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3693042]