Origin of the intermediate phase in lead zirconate, PbZrO 3

The so‐called intermediate phase of pure PbZrO 3 was investigated on a series of specimens by dielectric measurements and X‐ray diffraction. The results indicate that neither defects nor impurities are the origin of the phase. Only in specimens with a low content of pseudocubic [0 0 1] c domains does the intermediate phase appear on cooling. This preferred orientation suppresses the effect of out‐of‐phase oxygen octahedral rotations, which stabilize the antiferroelectric phase. As a result, the intermediate phase is present competitively in a narrow temperature range during cooling before the antiferroelectric phase transition.