Cation ordering in the microwave dielectric ceramic BaCd1/3Nb2/3O3

The crystal structures of the perovskite ceramic Ba(Cd1/3Nb2/3)O3 prepared by the molten salt method have been studied. The X-ray Rietveld method and selected-area electron diffraction apparently show an ordered trigonal structure. Furthermore Ba(Cd1/3Nb2/3)O3 exhibits a large perturbation away from the totally ordered structure and the ordering degree determined by the variations of the occupancies of Cd2+ and Nb5+ cations in B′/B″ sites is 0.443.