Transmission electron microscopy and neutron diffraction methods were used to characterize single crystals from the rhombohedral region of the Pb(Zr1-xTix)O3 phase diagram, where x ranged from 0.06 to 0.45. The electron diffraction patterns revealed the existence of superlattice reflections of the form, ½{hkl}p, where h = k = l, and ½{hk0}p, which were not observed in neutron powder diffraction studies. An analysis of these reflections revealed satellite spots, around the ½{hk0}p, which were associated with periodic antiphase boundaries. The origin of these superlattice reflections was explained in terms of the existence of local regions with anti-parallel cation displacements.

J.Ricote, D.L.Corker, R.W.Whatmore, S.A.Impey, A.M.Glazer, J.Dec, K.Roleder: Journal of Physics - Condensed Matter, 1998, 10[8], 1767-86