Local characterization of compositionally graded Pb(Zr,Ti)O3 thin films by scanning force microscope

Compositionally graded PZT thin film was prepared by a sol–gel technique. Nanoscale domain structure and polarization reversal behavior in an individual grain were investigated by means of scanning force microscopy (SFM) in piezoresponse mode. Domain as small as 30 nm in size was visualized. The observed complex domain contrast was attributed to the crystallographic orientation of the grains and to the built-in potential difference in compositionally graded PZT thin film under an ac field. The built-in potential difference, defect and space charge gave rise to strong domain pinning behavior during the polarization reversal.