It was recalled that, when a ceramic oxide in an applied electric field was subjected to extended irradiation with energetic particles at high temperatures, the electrical conductivity tended to increase. This phenomenon was called radiation-induced electrical degradation. Here, crystals of -phase material were subjected to a field of 1800V/cm and irradiated with 1.8MeV electrons at 773K. It was found that the conductivity increased above a critical dose. During the conductivity enhancement, the applied field was reversed and resulted in a decrease in conductivity. This demonstrated that radiation-induced electrical degradation was caused by carriers which were injected from the electrodes; together with electrons and holes that were created during ionizing irradiation. A model for radiation-induced electrical degradation was proposed in which the injected carriers were trapped mainly at impurities near to the electrodes; thus leading to the formation of dislocations. The latter served as traps for electrons and holes which were generated during ionizing radiation. A network of interconnecting dislocations was associated with the enhanced conductivity.

X.F.Zong, C.F.Shen, S.Liu, Y.Chen, R.Zhang, Y.Chen, J.G.Zhu, B.D.Evans, R.Gonzalez: Physical Review B, 1996, 54[1], 139-43