Pb2BaCuFeO5X (X = Cl, Br): New Intergrowth Compounds Composed of CsCl Type and Bipyramidal Defective Perovskite Blocks

Two new layered compounds, Pb2BaCuFeO5X (X = Cl, Br), have been prepared by a solid-state reaction. The structure of these compounds is an intergrowth of a defective perovskite BaCuFeO5 block unit and a cesium chloride type Pb2X layer. The structure is related to that of the mineral hematophanite by removing the central PbFeO3 layer; it is also related to that of layered cuprate YBaCuFeO5 by replacing the Y single layer with a Pb2Cl layer.