Properties of oxide and nitride ceramics after ion-heat modification

The parameters of the induced and biographical defects and their complexes in nitride ceramics, in single and in polycrystalline aluminium oxide after ion irradiation and following thermal annealing are studied. An influence of the defects on the charge transport and recombination process and on the optical absorption and photoconduction is determined. General characterist ics of defect formation in dielectrics having a different structure and ban d gap width were established. The localized states of defects an combined i nto a subband within the band gap as a result of the accumulation and inter action of the induced defects. The charge transport occurs by hopping mecha nism within the donor subband and in part by activation mechanism. The larg est change of conduction and optical properties is accompanied with Fermi l evel shift to the conduction band. (C) 2000 Elsevier Science B.V. All right s reserved.