Effects of specimen thickness and impurity on the conductivity of alumina under electron irradiation

The electrical conductivity of undoped (125, 332 and 545 μm-thick) and Cr3+ doped (332 μm-thick) α-Al2O3 single crystals was measured under electron irradiation at temperatures from 300 to 723 K. The conductivity under the ITER environment is found to be less than the limiting conductivity of 10−4 S/m required for insulators in ITER. Although the Cr3+ doping increases the electrical conductivity, it suppresses the radiation induced conductivity …