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 dependence of J[sub c] was measured. Depending on the relationship between J[sub c] and B, the irreversible magnetic field B[sub irr] was determined and pinning force density F was calculated. The experimental results showed that self-field-J[sub c] 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. [ABSTRACT FROM AUTHOR]