Enhanced high-field performance in PLD films fabricated by ablation of YSZ-addedYBa2Cu3O7−x target

Abstract

YBa2Cu3O7−x+Y2O3-stabilized ZrO2 (YBCO+YSZ) mixed filmswere prepared on SrTiO3/MgO substrates by pulsed-laser deposition from a YBCO target with a thin YSZ sector on top. TheJc at 77 K for themixed YBCO+YSZ thin filmwas enhanced. The Jc at 77 K for the pure film and the mixedYBCO+YSZ thin film were 1.46and 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 dependenceof Jc showed a broad peak at due to the flux pinning by the c-axis correlated defects. Elongated nanorods grown parallel to thec axis were consistently observed in the cross-sectional TEM images.