The Improved Critical Currents of MOD-Processed YBCO Thick Films With ( : Ce, Zr) and Y

We report the effects of barium-based perovskite particle inclusions of BaCeO₃ (BCO), BaZrO₃ (BZO), and YBa₂SnO_5.5 (YBSO) on the thickness dependence of critical current density (J_c) in metal organic deposition (MOD)-processed YBa₂Cu₃O_7-δ (YBCO) films on the SrTiO₃ (STO) single-crystal substrate. With increasing film thickness, while BZO-doped YBCO films show a serious degradation in J_c, caused by the interlayer at the boundaries of multicoated layers, BCO- and YBSO- doped films exhibit a significant enhancement of J_c (77 K, self-field) over ~1 μm thickness even though BCO- or YBSO- doped YBCO films have degraded in-plane textures compared with undoped films, implying that these perovskite dopants affect not only the pinning properties but also the growth of multicoated layers. The highest critical current (I_c) value over 440 A/cm-width, corresponding to J_c value of 1.8 MA/cm², was obtained from the 2.4-μm-thick YBSO-doped film.