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

Abstract

Ag/Bi-2223 tapes were fabricated using the Powder-In-Tube method, involyH1ĩ ntermediate deformation techniques of sandwich rolling (SR), pressing (P) and nQl1l1~r olling (NR). Magnetic field B depen:lence of J c was measured. Depending 6rt:~~' relationship between )c and B, the irreversible magnetic field Birr was determineli)lIl..W: pinning force density F was calculated. The experimental results showed that self-fiel%~;lb was linear with the relative density for SR-, P-and NR-tapes. Our experimental resftltss upport that NR-, P-, andSR-tapes have a same sort of pinning center and the interme#l~tl; deformation processing cannot change property of pinning centers, but can effectth §'" pinning force strength. Our experimental results also support that sandwich rolling istMb est technique for fabricating Ag/Bi-2223 tapes.