Ion irradiation effects on critical temperature of Bi₂Sr₂Ca₂Cu₃O_10-deltaand Bi₂Sr₂Ca₁Cu₂O_8-delta

Abstract

We have measured resistivity modification of Bi2Sr2Ca2Cu3O10- (Bi-2223) and Bi2Sr2Ca1Cu2O8- (Bi-2212) films H+, 100 keV He+ and 1 MeV O+ irradiation at normal incidence and at room temperature. It appears that degradation of critical temperature (Tc) follows the nuclear collision process or scales with the displacement per atom as in other high critical temperature superconductor (HTSC) oxides such as YBa2Cu3O7- (YBCO), assuming a displacement threshold energy of 20 eV. No significant difference of Tc degradation is observed between Bi-2223 and Bi-2212 phases. It is also found that Tc degradation of Bi-based HTSC oxide films is quite similar to that of Tl2Ca2Ba2Cu3O10- (Tl-2223), indicating that Bi-based and Tl-based HTSC oxides are more sensitive to ion irradiation than YBCO.