The Impact of Fe Doping on Jc Behavior of Bi2223/Ag Tapes under Magnetic Field

Abstract

Bi1.8Pb0.4Sr2Ca2.2Cu3—xFexOy silver‐sheathed (Bi2223/Ag) tapes with different Fe‐doping amounts, x = 0.001, 0.002, 0.003, 0.004, were fabricated by powder‐in‐tube (PIT) technique. It is found that the magnetic field dependence of critical current density Jc(H) is improved for samples with Fe‐doping amounts of x = 0.001, 0.002, and 0.003 at high magnetic fields, while the Jc(H) behavior deteriorates with Fe‐doping level increasing further. X‐ray diffraction analyses manifest that a small amount of Fe‐doping has little effect on the phase composition of Bi2223/Ag tapes. Scanning electron microscopy (SEM) observations do not show an obvious difference between un‐doped and Fe‐doped samples. It is concluded that the enhanced flux pinning originates from the introduction of effective pinning centers due to Fe ions partial substitution for Cu ions.