Enhanced high-field performance in PLD films fabricated by ablation of YSZ-added YBa₂Cu₃O_7−xtarget

Abstract

YBa2Cu3O7−x+Y2O3-stabilized ZrO2 (YBCO+YSZ) mixed films were prepared on SrTiO3/MgO substrates by pulsed-laser deposition from a YBCO target with a thin YSZ sector on top. The Jc at 77 K for the mixed YBCO+YSZ thin film was enhanced. The Jc at 77 K for the pure film and the mixed YBCO+YSZ thin film were 1.46 and 1.95 MA cm−2 (self field) (and 0.09 and 0.28 MA cm−2 (, B = 5 T)), respectively, even when both films were prepared using the same deposition conditions. The maximum pinning force of a doped film (77 K, ) was 15.9 GN m−3, which is comparable to the value reached by NbTi at 4.2 K. In the YSZ-added sample, the angular dependence of Jc showed a broad peak at due to the flux pinning by the c-axis correlated defects. Elongated nanorods grown parallel to the c axis were consistently observed in the cross-sectional TEM images.

Magnetization relaxation in YBCO films with improved supercurrent transport properties

“…To form Y 2 O 3 (YO) doped and BaZrO 3 (BZO) doped YBCO films, a "surface modified method" was used [3]. The same YBCO target was modified: a thin (0.5 mm thick) and narrow (area of about 2 ÷ 2.5 % of the surface area of the YBCO target) YO (or YSZ) sector was cut from YO (or YSZ) single crystal, respectively, and stuck on the YBCO target by silver paint.…”

“…Below we refer to experimental results obtained for a "pure" ~310 nm thick film (YBCO), a ~294 nm thick film with YO inclusions (YBCO YO), and for a ~317 nm thick film containing BZO nanorods, resulting from the reaction between ZrO 2 and YBCO while fabricating the film [3], and preferentially oriented along the c axis (YBCO BZO). In YBCO YO round-shaped YO inclusions of a mean diameter of 6−8 nm were randomly distributed (with a mean spacing of about 12 nm) and dispersed throughout the entire film thickness.…”

“…YBa 2 Cu 3 O 7−δ (YBCO) still represents one of the best choices for large scale applications of hightemperature superconductors (HTS), such as the fabrication of superconducting coated conductors [1], and the increase of vortex pinning through artificial routes is a field of intense activity [2][3][4][5][6][7]. It was found that BaZrO 3 inclusions in YBCO thin films, for example, significantly enhance vortex pinning for the external magnetic field H parallel to the c axis [2].…”

Thick YBa2Cu3O7−x+BaSnO3 films with enhanced critical current density at high magnetic fields

“…19 More than an order of magnitude improvement in J c was observed in 300 nm thick film samples as compared to YBCO samples of similar thickness at 5 T, H / /c. 10 Recently Mele et al 12 compared the performance of YBCO+ BZO and YBCO+ BSO thin films as well and showed that the films with BSO have higher pinning force. However, thick film ͑Ͼ2 m͒ performance in YBCO+ BSO films at high fields was not previously discussed.…”

Recent progress in high-<i>T</i>_C superconducting wires and their applications for electric power apparatus

“…The minimum J C generally occurs under a magnetic field applied perpendicularly to the film owing to the anisotropy of superconductivity in RE123. To increase this minimum J C , the introduction of pinning centers into RE23 superconducting films to stop the magnetic flux has been attempted, and the subsequent enhancement of J C under a magnetic field has been investigated [2,3,4,5,6,7,8]. The pinning centers with controlled shapes, sizes and densities are called artificial pinning centers (APCs).…”