Electron Microscopic Studies on Domain Structure of PbZrO3

The domain structure of a typical antiferroelectric substance, lead zirconate, is examined in detail fori the first time by electron diffraction and electron microscopy. The 90° and 60° domain configurations can be consistently understood on the basis of the pseudo-cubic unit cell. 180° domains, which are characteristic of the antiferroelectric phase, are observed. The displacement vectors between the domains are determined as ¼[21n], ¼[21̄n] and ¼[02n] (n=0 or 2) by the α-fringe theory for off-Bragg settings. Crystal structure images of the domains reveal how the unit cells connect across the domain boundary. 90° and 180° domains are found in the intermediate phase between the antiferroelectric and the paraelectric phases. The fact that 180° domains are observed is important evidence indicating that the phase is ferroelectric.