Synthesis and magnetic properties of 12L-perovskites Ba4LnIr3O12 (Ln=lanthanides)

New quadruple perovskite oxides Ba4LnIr3O12 were prepared and they form the perovskite-type structure with 12 layers, in which Ir3O12 trimers and LnO6 octahedra are alternately linked by corner-sharing. For Ln=Ce, Pr, and Tb compounds, an antiferromagnetic transition was observed at 10.5, 35, and 16 K, respectively.