Caracterización por medio de microscopía electrónica de transmisión de cerámicas de titanato zirconato de plomo con alto contenido en Zr

This work presents a Transmission Electron Microscopy (TEM) study of a series of ceramics with compositions Pb(Zr 1-x Ti x )O 3 (0.06≤x≤0.45). Two ferroelectric rhombohedral phases have been identified within this range of compositions. Besides the characterization of the domain configuration, TEM allows to obtain information of the local crystalline structure of these phases. One of the characteristics observed in these phases is the appearance of superlattice reflections at 1/2 {110} p and 1/2 {111} p positions of the electron diffraction patterns, which have not been observed by neutron or X-ray diffraction. They disappear when the paraelectric cubic phase is reached and with the increase of the Ti content. Dark field micrographs obtained with these reflections reveal details of the structures associated with them. The origin of these superlattice reflections has been attributed by other authors to a system of oxygen octahedra tiltings, which cannot explain the presence of some specific reflections. From the results we conclude that a more plausible explanation is the appearance of antiparallel displacements of cations.