Ion irradiation effects on critical temperature of Bi2Sr2Ca2Cu3O10-δ and Bi2Sr2Ca1Cu2O8-δ

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