DC and AC electrical conduction in single crystal alumina

Abstract

The conductivity and permittivity in the c-direction of single crystal boule sapphire slices and flux grown platelets have been measured over a temperature range of 700 to 1500°C, an oxygen partial pressure range from 1 to 2 × 10−2 at, at dc, and over a frequency range from 70 Hz to 5 MHz. A surface and a bulk process are postulated, and the electronic or ionic nature of the latter discussed.