From rocksalt to perovskite: a metathesis route for the synthesis of perovskite oxides of current interest

Abstract

Solid state metathesis reactions between lithium containing rocksalt metal oxides and appropriate lanthanum/alkaline earth metal oxychloride/chloride provide a convenient route for the synthesis of several perovskite oxides of current interest, such as LaCoO₃, LaMnO₃, AMnO₃ and ATiO₃ (A = Ca, Sr, Ba). Similarly, metathesis reactions between Li₂TiO₃/Li₂ZrO₃ and PbSO₄ (instead of PbCl₂) yield PbTiO₃, PbZrO₃ and PbZr_{1 − x}Ti_xO₃ perovskites. BaPbO₃ and superconducting BaPb_0.75Bi_0.25O₃ could also be synthesized by the metathesis reaction between Li₂PbO₃/Li₂(Pb,Bi)O₃ and Ba(OH)₂·8H₂O. Uniformly in all cases, the perovskite oxides were obtained in the form of loosely connected submicron sized particles at considerably lower temperatures than those usually employed for their synthesis by ceramic methods.