High‐Temperature Dielectric Behavior of TiO2(Rutile)

Abstract

The dielectric behavior of “a” and “c” orientation single crystals of (rutile) was investigated as a function of frequency, from 100 Hz to 500 kHz, and temperature, over the interval from 500° to 1000°C. The a‐c conductivity at low applied voltages was found to be due to electronic carriers throughout the frequency and temperature range studied. The dielectric polarization processes occurring in this material were found to depend on the temperature and frequency ranges being investigated. At frequencies above 105 Hz, electronic and lattice polarization was found to predominate throughout the temperature interval investigated. The lower frequency data could be rationalized on the basis of a space‐charge polarization model involving mobile point defects, which are blocked or partially blocked at the electrodes, and electronic carriers, which are able to pass through the electrode. At temperatures below 750°C, the “c” orientation specimens were found to exhibit an anomalous behavior that was felt to be the result of a thin barrier layer in the vicinity of the specimen electrodes.