Enhancing superconductivity of ultrathin YBa2Cu3O7-δ films by capping non-superconducting oxides

Enhancing superconductivity of ultrathin YBa₂Cu₃O_7-δ films by capping non-superconducting oxides

Bo Hai¹, Ren Tianshuang¹, Chen Zheng¹, Zhang Meng¹, Xie Yanwu^{1, 2, †}

(a) RHEED intensity oscillations and (b) atomic force microscope (AFM) image of a 5-uc YBCO film grown on TiO₂-terminated SrTiO₃ substrate. (c) RHEED intensity oscillations and (d) AFM images of a 5-uc YBCO film grown on SrO-terminated SrTiO₃ substrate that is made by inserting 1-uc SrO layer on the TiO₂-terminated SrTiO₃. Insets in panels (a) and (c) show the sample configuration. The root mean square roughness of panels (b) and (d) is 0.41 nm and 0.52 nm, respectively. Lower panels in panels (b) and (d) show the typical height profiles along the white cross lines.