Effect of various mechanical deformation techniques on pinning force densities in Ag/Bi-2223 tapes

Ag/Bi-2223 tapes were fabricated using the Powder-In-Tube method, involving intermediate deformation techniques of sandwich rolling (SR), pressing (P) and normal rolling (NR). Magnetic field B depedence of Jc was measured. Depending on the relationship between Jc and B, the irreversible magnetic field Birr was determined and pinning force density F was calculated. The experimental results showed that self- field Jc was linear with the relative density for SR-, P- and NR-tapes. Our experimental results support that NR-, P-, and SR-tapes have a same sort of pinning center and the intermediate deformation processing cannot change property of pinning centers, but can effect the pinning force strength. Our experimental results also support that sandwich rolling is the best technique for fabricating Ag/Bi-2223 tapes.