Observation of polarization reversal processes in Pb(Zr,Ti)O/sub 3/ thin films using atomic force microscopy

The piezoresponse-imaging technique using atomic force microscopy (AFM) provides a substantial understanding of the polarization reversal process of ferroelectric thin films at the nanoscale level. In this study, in order to investigate the polarization reversal process and its dynamics in Pb(Zr,Ti)O/sub 3/ (PZT) thin films, we examined the dependence of the switched area on the width of the switching pulse. The area of the switched domain increased from 2 /spl times/ 10/sup -3/ to 3 /spl times/ 10/sup -1/ /spl mu/m/sup 2/ as the pulse width increased from 500 ns to 100 ms. The switched area rapidly increased in the initial polarization process as the applied pulse width increased. However, the switched area stopped expanding at the grain boundaries and domain growth over grain boundaries was not observed.