Incommensurately modulated structures in Pb(Zr1−xSnx)O3 single crystals by x-ray diffraction

Pb(Zr1−xSnx)O3 single crystals were characterized using x-ray diffraction as a function of temperature and composition. The information on the structure of two intermediate phases, situated between antiferroelectric and paraelectric phases in the composition–temperature phase diagram, has been obtained. The lower-temperature intermediate phase is characterized by incommensurate displacive modulations in the Pb sublattice. The higher temperature intermediate phase is characterized by distortions of the oxygen sublattice primarily in the form of anti-phase tilts of the oxygen octahedra. The structured diffuse scattering was also observed in the paraelectric phase along Γ–M and M–R lines pointing to the high-temperature correlated disorder of Pb ions and octahedral rotations, respectively.