Electrical And Thermal Properties Of Ca5mg4_xcox(Vo4)6 (0 < X < 4), A Promising Electrode Material

The garnet-type solid solution Ca5Mg4_xCox(VO4)6 (0 < x < 4) synthesized through a solid-state reaction between the intermediates Ca3V2O8, Mg3V2O8 and Co3V2O8 crystallizes in cubic space group Ia3d (Z = 8) that has been confirmed by Rietveld refinement. Thermal stability has been checked from room temperature to the melting point which is 1168 degrees C maximum for Ca5Mg4(VO4)6. The cobalt-doped vanadates demonstrate predominantly electronic conductivity about 10-2 S.cm_ 1 at 850 degrees C. The coefficients of thermal expansion vary from 12.10_6 K_ 1 to 16.10_ 6 K_ 1.