Characterization of TiO2‐Based Sensor Materials Using Immittafice Spectroscopy

The ac electrical data, monitored in the frequency range 5 Hz [<=] f [<=] 13 MHz, are used to establish the microstructure-property response of titania-based composite polycrystalline sensor materials. These electrical data, when analyzed utilizing the lumped parameter/complex plane analysis, reveal several contributions form simultaneously operating mechanisms to the terminal admittance of the grain boundary. The nature of the electrically conducting paths, consisting of the lumped series-parallel network in the microstructure, is suggested via an equivalent circuit representation incorporating the underlying mechanisms in a systematic manner.