High rate deposition of thick YBa₂Cu₃O_7−<i>x</i>superconducting films using low-fluorine solution

Abstract

We have developed a new solution for fabrication of YBa2Cu3O7−x (YBCO) films. This new solution contains only 30% of the fluorine content in an all-TFA solution, and the duration of the heat-treatment cycles is much shorter than that when the traditional all-TFA solution is used. Pyrolyzed films with mirror-like surfaces can be obtained at a high heating rate of 10 °C min−1. Therefore, thick YBCO films can be prepared rapidly using a multiple coating–pyrolysis process. Using low-fluorine solution, Y and Ba fluorides (YF3 and BaF2) were formed during the pyrolysis process, which is the same as when an all-TFA solution was used. Hence, a liquid phase was formed prior to the YBCO nucleation, which enhanced the epitaxial growth of the YBCO film as well as its superconducting performance.