Electric circuit model for MgO-doped ZrO2-TiO2 ceramic humidity sensor

The MgO-doped ZrO2-TiO2 ceramic pellets were studied for its humidity-sensi tive electrical conduction. An equivalent circuit model has been proposed t o define the humidity-sensitive electrical properties. This model is in agr eement with the experimental findings. The electrical conduction is largely controlled by the intergranular impedance except at very high humidities. The impedance of the pellets showed inductive behavior in high-humidity reg ion. This behavior can be attributed to the spherical paths adopted by char ge carrier because conduction is mainly through the spherical grain surface . (C) 1998 American Institute of Physics. [S0003-6951(98)01152-8].