NEUTRON-IRRADIATION EFFECTS IN HIGH-TC SINGLE-CRYSTALS

In this contribution, the influence of fast neutron irradiation on various properties of YBa2Cu3O7-delta and Bi2Sr2CaCu2O8 single crystals is reviewed. The main experimental findings may be summarized as follows. Up to fluences of about 1 x 10(22)m-2 (E > 0.1 MeV) significant enhancements of J are achieved especially at high temperatures. The irreversibility lines of both compounds are shifted, but not in the same way and depending on field orientation. The relaxation rates in YBCO decrease. Many of these observations can be described by an interplay of strong flux pinning related to radiation-induced defect cascades, weak flux pinning by the pre-irradiation defect structures, and intrinsic pinning by the Cu-O layers.