EFFECT OF INTERMEDIATE ROLLING ON THE TRANSPORT PROPERTIES OF (Bi1.6Pb0.4)Sr2Ca2Cu3O10 SUPERCONDUCTOR TAPES WITH NANO NiFe2O4 ADDITION

Abstract

The effects of nano sized NiFe₂O₄ addition in (Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O₁₀ (Bi2223) superconductor tapes were investigated. The (Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O₁₀ powders were prepared by using coprecipitation technique and the tapes were prepared by using the powder-in-tube method (PIT). 0.01 wt% nano sized NiFe₂O₄ (13 nm) was added to the powders as this ratio of nano NiFe2O4 optimized the critical current density (Jc) of bulk samples based on our initial studies. The effects of intermediate rolling on the transport critical current density of the (Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O₁₀-(NiFe₂O₄)0.01 tapes were investigated. The transport critical current density at 30 K was 17870 A/cm² for tapes sintered for 50 hours without intermediate rolling. Intermediate rolling up to two times increased the J_c at 30 K to 32700 A/cm². Intermediate rolling improved the Jc of the tapes by 83 % compared to tapes without intermediate rolling.