Abstract
Two “Melt-Powder-Melt-Grown” YBa2Cu3O7-δ samples were prepared, oriented and analyzed by optical and x-ray methods. The first sample contains 12.8 wt% of the 211-phase and 4.7 wt% of metallic silver, the second 17.5 wt% 211 and 7.4 wt% silver. The samples were investigated by ac susceptibility and by the flux profile technique to evaluate the critical current densities. The samples were repeatedly irradiated with fast neutrons to fluences ranging from 2·1021 to 6·1021 m−2 (E003E0.1 MeV). As observed on single crystals, Jc shifts to higher values. However, the enhancement factors are not particularly high (~10) and vary with temperature in a rather unusual way. A small “fishtail” effect measured on the unirradiated samples at various temperatures disappears after neutron irradiation. The irreversibility lines (IL) do not show strong enhancements upon neutron irradiation. For H||c the IL increases, whereas slight decreases are observed for Blab. This behavior of the IL was observed on both samples. The fluence dependence of Jc and the IL’s is compared with results obtained on single crystals.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
