Construction of a double-layered tetrahedral network within a perovskite host: Two-step route to the alkali-metal-halide layered perovskite, (LixCl)LaNb2O7

Abstract A two-step topotactic route is used to construct lithium halide layers within a perovskite host. Initially RbLaNb 2 O 7 is converted to (CuCl)LaNb 2 O 7 by ion exchange and then reductive intercalation with n -butyllithium is used to form (Li x Cl)LaNb 2 O 7 . The copper metal byproduct from the reduction step is removed by treatment with iodine. Rietveld refinement of neutron powder diffraction data revealed that an alkali-halide double layer with LiO 2 Cl 2 tetrahedra forms between the perovskite slabs. Compositional studies indicate that the range for x in (Li x Cl)LaNb 2 O 7 is 2⩽ x