90° domain reorientation and domain wall rearrangement in lead zirconate titanate ceramics characterized by transient current and hysteresis loop measurements

The polarization switching in Pb(Z(r),T-i)O-3 (PZT) ferroelectric bulk ceramics undoped and doped with Nb2O5 or Fe2O3 was studied by means of both hysteresis loops and transient current measurements at room temperature. The results obtained revealed that in PZT ceramics, during the poling process, the reorientation of the polarization may be interpreted as resulting of two contributions: two 90 degrees domain reorientation followed by 90 degrees domain wall rearrangement. 90 degrees domain reorientation is field dependent and responsible for a shoulder observed in the transient current curves, while domain walls contribution is nearly field independent and occurs for longer time. 90 degrees domain wall rearrangement enabled an increase of about 40% of the total polarization in the samples. The reorientation behavior of the domains showed to be strongly influenced by the type of impurity and by the electrical field strength. (C) 2001 American Institute of Physics.