Cluster-glass behavior of a highly oxygen deficient perovskite, BaBi _0.28Co_0.72O_2.2

A highly oxygen deficient perovskite, BaBi_0.28Co _0.72O_2.2, was synthesized by solid state reaction. The crystal structure was determined by means of neutron and x-ray powder diffraction. The material exhibits semiconducting behavior with an energy gap of 1.8eV. The electron diffraction study does not reveal long range Bi:Co ordering; instead it shows the existence of short range ordering in this phase. The AC and DC magnetic susceptibility studies reveal cluster-glass behavior, which has its origin in the interacting ferromagnetic clusters present.