Analysis of the electrical behaviour of conductor/insulator composites using effective medium theories

Al2O3/8YSZ composites with a wide range of alumina compositions, from 0 to 50 wt.%, have been prepared and characterised. The electrical properties and the microstructure were studied by complex impedance spectroscopy and scanning electron microscopy techniques, respectively. Simple models derived from effective medium theories were used to predict the qualitative trend of electrical conductivity versus Al2O3 volume fraction and a comparison with the experimental data is reported.