High pressure synthesis and structure of a new magnetoplumbite-type cobalt oxide SrCo12O19

A new magnetoplumbite-type hexagonal cobalt oxide, SrCo12O19, has been synthesized at a high pressure of 3 GPa and its structural and magnetic properties have been studied using single crystalline samples. Bond-valence calculations for five crystallographically independent Co sites show a rather wide charge distribution from +2.15 to +3.50. Magnetic measurements have revealed anisotropic magnetic behavior below a magnetic ordering temperature of 80 K. Comparative discussions on the structure–property relationship for SrCo12O19 and related compounds suggest the presence of localized spins with a uniaxial anisotropy at the trigonal bipyramidal site.