Abstract
This paper is concerned with the humidity dependence of resistivity of potassium-modified ferric oxide ceramics which show the bulk-type sensitivity for ambient humidity. The potassium-modified ferric oxide ceramics show remarkable dependence of resistivity on humidity, especially in low humidity range less than 50% relative humidity and at an ambient temperature from 0°to 100°C. The effects of composition, sintering temperature, microstructure, and reaction product on humidity dependence of resistivity are discussed. The sensitivity on humidity is due to ionic conductivity in or on, small. grains of potassium-(β+β") hematite caused by adsorption of diffused moisture through the pore of sintered discs.
