K3Sb4O10(BO3): A solid state K-ion conductor

The ionic conductivity of potassium boroantimonate K3Sb4O10(BO3) is studied between 300 and 750 degrees C by AC complex impedance measurement. Ball-milling of the powder prepared by solid state reaction at high temperature increases significantly the relative density of the sintered pellet and therefore the conductivity level which is about 1.5 x 10(-4) S cm(-1) at 400 degrees C. The addition of a glass-type sintering aid increases similarly the relative density but has a detrimental effect over the conductivity level. The low activation energy of K3Sb4O10(BO3) compound, Ea = 0.325 eV, is related to the diffusion of K+ ions through interconnected 1D-tunnels.