Synthesis, structure, and magnetism of BCC KIrO₃

KIrO₃in the body-centered cubic variant of the KSbO₃-type structure is reported. Black cube-shaped single crystals, obtained from the solid-state reaction in a half-closed silver capsule in a sealed quartz tube, were used for the structural characterization by single-crystal X-ray diffraction. The material, space groupIm3̄ (no. 204), exhibits a disordered K array and a three-dimensional (3D) IrO₆-based tunnel-like framework. Temperature-dependent magnetization and heat capacity measurements suggest a paramagnetic state for KIrO₃, with significant contribution of temperature independent paramagnetism and without any sign of long-range magnetic ordering (down to 1.8 K). The 3D motif of this material, based on the 5d Ir⁵⁺ion, is of interest for investigating unconventional magnetism.