Characterization of YBCO coated conductors deposited by LPE on MgO substrates

Results on the field and temperature dependence of the: critical transport current density in YBa2Cu3O7-delta coated conductors of various thickness a re presented. The conductors were deposited by liquid phase epitaxy on RE-1 23 buffer layers on MgO substrates. The analysis of the remanent fields in magnetization loops with different maximum external field provides informat ion about the inter- and intragrain current distribution. From the reverse leg of the magnetization loops the average grain size in the YBCO layer can be estimated. The results of these magnetic measurements are compared to t hose obtained from magneto-optical imaging. Modifications of the defect str ucture by neutron irradiation are reported as well. The resulting defects a re either collision cascades, originating from fast neutrons (E > 0.1 MeV), or point defects, originating from neutrons with lower energies. Their inf luence on J(c) will be discussed.