Local Structure Analysis of A TiO 3 ( A = Sr, Ba, Pb).

The atomic-scale structure of Ti-related perovskite materials, ATiO3(A= Sr, Ba, Pb), has been studied using high-energy X-ray diffraction, Rietveld refinement, and the atomic pair-distribution function technique. It was found that the local structures of BaTiO3and PbTiO3deviate from their average structures. We also found the tetragonal distortion in their middle-range-order structures (∼ 7 Å). The temperature dependence of the middle-range-order structures showed that an order-disorder character exists in BaTiO3and a displacive-type character exists in PbTiO3. [ABSTRACT FROM AUTHOR]