Enhanced high-field performance in PLD films fabricated by ablation of YSZ-added YBa2Cu3O7−xtarget

YBa 2 Cu 3 O 7− x +Y 2 O 3 -stabilized ZrO 2 (YBCO+YSZ) mixed films were prepared on SrTiO 3 /MgO substrates by pulsed-laser deposition from a YBCO target with a thin YSZ sector on top. The J c at 77 K for the mixed YBCO+YSZ thin film was enhanced. The J c 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 J c 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.