Modification on the surface of superconducting YBa2Cu3O7-x films by microwave plasma-enhanced pulsed laser deposition

Superconducting YBa2Cu3O7−x films having smooth surfaces were successfully synthesized by a microwave plasma‐enhanced pulsed laser deposition (PEPLD) process. Particulates that frequently occurred in films grown by the conventional PLD process were effectively eliminated. The films were epitaxial‐like. The c‐axis was perpendicular to the films’ surface, the a and b axes were aligned in the films’ plane, and the onset and zero of the transition temperature were at Tc=90 K and Tc0=86 K, respectively. Optical emission spectroscopy indicated that the presence of oxygen plasma not only reexcited the laser‐induced species via the collision process, but also produced abundant atomic oxygen in PEPLD process. The surface reaction kinetics for the formation of the thin‐film process was thus greatly enhanced, which substantially improved the thin‐film quality.