The so-called reference remanent polarization and reference remanent in-plane strain are calculated from a set of creep data of a PZT wafer subjected to constant through-thickness electric fields at high temperatures. Using the calculated reference remanent quantities, domain switching processes at different temperatures are compared with each other. From the macroscopic comparison, it is found that the fraction of the variants aligned parallel to the plane of the wafer decreases with increase in temperature during an electric field-induced polarization reversal. Other interesting phenomena were also observed and all of them were discussed from the view point of 90 degrees domain switching. (C) 2011 Elsevier B.V. All rights reserved.