EFFECT OF ELECTRON-IRRADIATION ON BI(2)SR(2)CACU(2)O(8)AND BI2SR2CUO6SUPERCONDUCTORS

The effect of electron-irradiation induced defects on the superconduct ing transition temperature (T-c), on the normal-state resistivity and the stability of defects on thermal cycling were studied in Bi2Sr2CaCu 2O8 and Bi2Sr2CuO6 superconductors. It was found that T-c/T-c0 is abou t three times less sensitive to irradiation-induced defects in the for mer than in the latter compound. We show that the ab plane resistivity increase in both compounds is due to the decrease of the mean free pa th caused by defects created in the CuO2 planes. The defects start to anneal above 100 K and, at 300 K; only 50% of the low-temperature defe ct concentration is left.