The conductivity of polycrystalline spinels was measured, using alternating-current techniques, at temperatures of between 25 and 500C. The conductivity at 200C was equal to 1.9 x 10-3S/cm, and the conductivity at 400C was equal to 6.3 x 10-2S/cm. The data for temperatures ranging from 100 to 490C indicated an activation energy of 51kJ/mol.

R.Kanno, Y.Takeda, O.Yamamoto: Materials Research Bulletin, 1981, 16[8], 999-1005