Structural Peculiarities of the Intermediate Phase in Zr-Rich Lead Zirconate Titanate

Resumo

This paper presents the results of X-ray diffraction studies on a single crystal of lead zirconate titanate PbZr_0.993Ti_0.007O₃ in the region of existence of an intermediate ferroelectric phase. In addition to the known superstructure reflections of the M type q_M = \(\left\{ {\frac{1}{2},\frac{1}{2},0} \right\}\) and the first-order satellite reflections q_M + {δ, δ, δ}, unknown second-order satellites have been observed near q_M and near the Bragg reflections. Structural model of regular system of antiphase domains is used for diffraction calculation. The model is shown to describe the first- and second-orders satellite reflections in the vicinity of q_M, but it cannot explain the appearance of satellites around the main Bragg peaks. A possible origin of the system of the superstructures observed in the intermediate phase is discussed.