Influence of glass content on microstructure and electrical conductivity of a β-alumina thick film

The electrical properties of porous beta -Al(2)O(3) glass pellets and thick films of same composition are investigated by means of impedance spectroscopy measurements. For both pure beta -Al(2)O(3) and glass pellets, the recorded blocking effect is related to porosity. The introduction of a low conducting glassy phase in an alumina matrix results in a low frequency additional blocking contribution which describes the proper response of a reaction product layer. For thick films, the impedance diagram is only composed of a low frequency semicircle. The corresponding large blocking effect is interpreted in terms of an increasing wetting of beta -alumina grains by the glass.