Electrical Properties of Ceramic Oxides Containing One-dimensional Co-Co Chains

Abstract

Polycrystalline sample of Sr₆Co₅O₁₅, which is one of (A₃Co₂O₆)_m(A’₃Co₃O₉)_n[A, A’:Ca, Sr, Ba] homologous series (Sr₆Co₅O₁₅,m=3,n=3), was prepared by solid state reaction. Electrical resistivity of Sr₆Co₅O₁₅; showed semiconductive behavior from 5 to 9×10² Ωcm in 300∼1120 K. Seebeck coefficient showed positive value (110-150 μV/K). In 350-1120 k, the maximum value of power factor was 0.020×10^-3 W/(m·K²) at 1100 K, which was larger than that of Ca₃Co₂O₆(0.012×10^-3 W/(m·K²)).