Characteristics of ZnO-based semiconductor ceramics doped with GeO2 and PbO

The effect of GeO2 and PbO on physical, microstructure, and the electrical properties of ZnO based ceramics is investigated. A decrease in water absorption was recorded with rise in maturing temperature and increase in time of soaking. A minimum water absorption was displayed in specimens fired at 1000 oC for 2 hours. The average grain size decreases initially as GeO2 content increases up to 2 mol %. The grain size of ZnO decreases greatly, as the Ge-rich phase inhibits grain growth ZnO decreases. The decrease of capacitance in (pf), dielectric constant (-) and consequently increase (AC) conductivity with increasing frequency (1-20) KHz was investigated.