ABSTRACT
Recent results have shown that impedance spectroscopy can be used for crack characterisation in electric ceramics. The capacitive component of the blocking effect and its relaxation frequency appear to be as significant as the resistive term. Appropriate combinations of these parameters allow us to evaluate the average width of the cracks. Measurements performed on welds between single crystals and porous materials have confirmed this statement. They have also revealed a serious risk of error in the determination of the specific conductances in highly porous and composite materials.
