PEROVSKITE-LIKE SOLID-SOLUTIONS IN THE SYSTEM LITAO3-CAZRO3

An investigation of the LiTaO3-CaZrO3 phase diagram has been carried out and the solid solution limits redetermined. LiTaO3 solid solutions extend from 0 to 20 mole% CaZrO3. CaZrO3 solid solutions cover the range 27 to 100 mole% CaZrO3, but are incomplete since a two-phase region or immiscibility gap occurs over the range ∼ 88 to 95 mole% CaZrO3. The crystal structures of two perovskite-like CaZrO3 solid solutions, one on either side of the immiscibility gap, were determined by Rietveld refinement of powder neutron diffraction data. The structures of these perovskite-like materials are compared and possible causes of the solid solution immiscibility are discussed. © 1994 Academic Press, Inc.