Carrier doping in the layered cuprate Sr₁₄Cu₂₄O₄₁

We have made a trial of carrier doping into the layered cuprate Sr₁₄Cu₂₄O₄₁ with the CuO₂ chain and the Cu₂O₃ plane by the partial substitution of Ca²⁺ for Sr²⁺ and the annealing in oxygen of various pressures. In Sr_14-xCa_xCu₂₄O₄₁, the electrical resistivity ρ{variant} decreases with increasing x, though the temperature dependence still remains semiconductive. The magnetic susceptibility exhibits an anomalous broad hump about 70 K for x=0. Through the annealing N₂, the value of ρ{variant} decreases slightly and a tiny anomaly appears about 20 K for 8.4≦x≦9.0.