Impedance studies of the cell Pt(Na, Sr)β″-aluminaPt

Abstract The present work confirms that the temperature range in which the conductivity of polycrystalline (Na, Sr) β″-aluminas can be obtained by two-probe or four-probe measurements depends upon the composition. A separate determination of the inter- and intragranular resistance is feasible in a limited temperature range for each compositions. The intragranular resisivity of the polycrystalline materials is considerably smaller than the total resistivity. The activation energy of the intragranular conductivity is lower than that of the total conductivity and shows an increase with the Sr content. The activation energy of the total conductivity increases strongly with the Sr content and passes through a maximum.