Strong Flux Pinning by Magnetic Interlayers Compatible With ${\rm YBa}_{2}{\rm Cu}_{3}{\rm O}_{7-\delta}$

Abstract

A multilayer thin film comprising pure YBa2Cu3O7-δ (YBCO) interlayered with heavily YFeO3- doped YBCO has been fabricated on a vicinal-cut SrTiO3 substrate, thereby separating geometrically the contributions of the intrinsic flux pinning due to the YBCO ab planes and the pinning due to the magnetically-doped interlayers. It is consequently found that the magnetic planes provide flux pinning of a strength comparable to the intrinsic pinning in YBCO at low fields, highlighting the efficacy of YFeO3 as a magnetic pinning additive for YBCO, and emphasizing that in contrast to pinning by normal-state material, pinning by magnetic material is strongest at low applied fields.