Synthesis and Electrical Property of Novel Compound, K_xCa_x/2Sn_8-x/2O₁₆(X≤2) with Hollandite Struture

Abstract

A new tin oxide, K_xCa_x/2Sn_8-x/2O₁₆ (x≤2) with the hollandite type structure was synthesized at 973 K-1473 K in air by a conventional ceramic process. Its structure was classified as monoclinic symmetry with the lattice parameters of a=1.5006(1)nm, b=0.32108(1)nm, c=1.0608(1)nmand, β=134.954(6)°. The well-grown fibrous aggregation was observed in the melted K₂CO₃. Its electrical conductivity and activation energy were estimated to be about 2.2 × 10^-9 Ω^-1·m^-1 (room temperature) and 0.63 eV. Accordingly, the ionic conduction was substantially governed by the migration of ions from site to site in the tunnel.