Critical current degradation behavior of 7-filamentary Ba_1−x K _x Fe₂As₂ tapes under uniaxial strain

Abstract

122-type iron-based superconductors (IBS) have attracted extensive attention due to their excellent performance. The 100-m class Ba1-xKxFe2As2 (Ba-122) 7-filamentary IBS tapes were successfully fabricated in Institute of Electrical Engineering, Chinese Academy of Sciences. This study has performed the tests of the 7-filamentary Ba-122 short tape samples (Bas samples) and the 100-m class 7-filamentary Ba-122 tape samples (Ba100 samples) under various kinds of strain by the U-shaped bending spring devices. Both types of samples were still reversible even when the applied compressive strain reached -0.65%. In addition, the reversible tensile strain limit of the Bas and Ba100 samples were 0.25% and 0.28%, which increased to 0.38% and 0.41% after considering the effect of the cooling process.