Dielectric responses of the layered cobalt oxysulfide Sr₂Cu ₂CoO₂S₂ with CoO₂ square planes

The dielectric responses of the layered cobalt oxysulfide Sr ₂Cu₂CoO₂S₂ with the CoO₂ square planes were analyzed. The thermopower, dielectric constant, resistivity and ac conductivity of the polycrystalline samples were measured in order to analyze the effects of magnetic excitations on charge transport of the sample. It was observed that the resistivity of the sample was increased like a semiconductor, and the thermopower was decreased like a metal, with decreasing temperature below the Ne^́el temperature. The dielectric relaxation of the sample was found to be depended on the temperature and was correlated to the magnetic states.