Planar faults in layered Bi-containing perovskites studied by X-ray diffraction line profile analysis

Profile fitting procedures associated with integral breadth studies and Fourier analysis are applied to the study of the complex Bi-containing layered perovskite SrBi₂Nb₂O₉. Strong line broadening anisotropy is evidenced. Both `size' and `strain' effects contribute to the observed width. However, `size' broadening along the [00l] direction is essentially caused by stacking faults. The coherently diffracting domain sizes are deduced from Fourier analysis of the diffraction patterns and a rough estimate of the mean distance between faults is given. Thermal annealing significantly decreases the stacking fault density.