Tuning of the critical current in YBa₂Cu₃O_7−xthin films by controlling the size and density of Y₂O₃nanoislands on annealed SrTiO₃substrates

Abstract

We introduced high density columnar defects, as artificial pinning centres (APCs) for quantized vortices, into YBa 2 Cu 3 O 7−x (YBCO) films during the film deposition procedure. APCs were introduced perpendicular to the film surface using nanosized Y 2 O 3 islands prepared on SrTiO 3 (100) substrates by pulsed laser deposition. Varying the deposition parameters and the substrate annealing conditions allowed strong changes in the shape and density of the Y 2 O 3 islands to be induced. The best performance among the APC samples as compared to the pure YBCO film was obtained for that grown on the Y 2 O 3 -deposited substrate with five laser pulses, corresponding to 0.2 Y 2 O 3 monolayers (ML). Even when the 0.2 ML APC films were prepared using the same deposition conditions, the columnar defects enhanced J c at 77 K from 1.8 to 2.7 MA cm −2 (self-field) and from 0.06 to 0.10 MA cm −2 (H = 5 T).

Tuning the superconducting properties of YBa2Cu3O7 tapes grown by chemical methods

“…Growth of YBCO on top of vacuum deposited metallic (Ag) and oxide (CeO 2 , Y 2 O 3 ) nanotemplates have evidenced an influence in the vortex pinning properties [12,13]. On the other hand, we have recently shown that surface roughness of the underlying CSD buffer layers can also improve the field dependence of J c in TFA-YBCO thin films [14].…”

Systematic study of BaSnO3 doped YBa2Cu3O7−x films

“…Several nano-engineering techniques were recently developed to insert and control APCs and, as a consequence of this, the transport performances of YBCO and REBCO films were dramatically enhanced. Many research groups were involved in the challenge of increasing the performance of coated conductors (CC) by APCs, and a lot of papers were published on this topic so far [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

Characterization of Complex Spintronic and Superconducting Structures by Atomic Force Microscopy Techniques

“…Several ways of externally inducing normal regions in superconductors have been demonstrated. They include: irradiation by swift heavy ions, artificially introduced regular arrays of holes, artificially introduced nanoparticles that create columnar defects in superconducting films, or surface decoration of the substrate upon which the superconducting film is grown (Civale et al, 1991;Augieri et al, 2010;Mele et al,2006;Sparing et al, 2007). However, classic nonmagnetic pinning becomes ineffective at high temperatures making it difficult to imagine practical applications of HTS materials.…”