Jc of Sm 1+xBa 2−xCu 3O y films improved in the whole angle range by introducing BaZrO 3 nanoparticles

Abstract

For an enhancement of J c under applied magnetic fields, introducing BaZrO 3 (BZO) into REBa 2Cu 3O y (REBCO) is effective. However, there have been few reports on the comparison of configurational effect of BZO on the crystallinity, superconducting properties and microstructures in REBCO films. In this study, we fabricated 2 vol.% BZO-doped Sm 1+ x Ba 2− x Cu 3O y (SmBCO) films by pulsed laser deposition with two different methods during deposition; using BZO-doped SmBCO target (BZO-mixed SmBCO), and alternating SmBCO and BZO targets (BZO-layered SmBCO). The angular dependence of J c (77 K, B = 1 T) in the BZO-mixed SmBCO film exhibited strong peak in the direction parallel to the c-axis, while the J c of the BZO-layered SmBCO film was enhanced in the whole field angle range. From a microstructure analysis, nanosized BZO-particles were observed in the BZO-layered SmBCO film and they acted as isotropic pinning centers.