The effect of electron irradiation on the critical temperature and magnetoresistance of multiple-strand Ag/Bi2223 tapes

Abstract

The effect of 2 MeV electron irradiation at 300 K on the critical temperature (T c ) and magnetoresistance (R B) at T < T c of Ag/Bi2223 tapes is investigated. It is shown that a slight increase in T c and abnormal reduction of R B are observed at low irradiation doses (∼1014 cm−2). At higher doses (∼1015 cm−2) or longer storage of irradiated specimens at 300 K, a decrease in T c and an increase in R B are observed. Variations in the critical parameters of tapes upon electron irradiation are controlled by a spatial grid of tunnel Josephson transitions at intercrystallite boundaries. It is assumed that an increase in R B is caused by accumulation of defects at the intercrystallite boundaries. The revealed anomalous decrease in R B is related to pinning of the magnetic flux at radiation-induced defects in Bi2223 microcrystals.