Short-range order phenomena in lead-based perovskites

Abstract

The electron diffraction patterns of many monocrystalline and polycrystalline lead-based perovskites have common superstructure features consisting of weak {h+1/2,k+1/2,O} spots, together with rods of diffuse scattering in 〈110〉 reciprocal lattice directions. These superstructure phenomena are thought to be associated with the short-range ordering of lead-site vacancies to form microregions with an I-centred 2ao x 2ao x 2ao superlattice.