EFFECT OF STEPWISE DOPING OF Al2O3 AND Li2O ON MICROSTRUCTURE AND ELECTRICAL RESISTIVITY OF ZnO CERAMICS
Porous and high-resistive ZnO ceramics were obtained by a stepwise doping method of Al2O3 and Li2O. Lithia increased the resistivity of ZnO doped with Al2O3 without a change of porous microstrucrure. The sensitivities of the stepwisely doped specimens to reducing gases at 300°C were improved compared to that of the singly doped specimens.