Influences of HF Gas Generation on Advanced TFA-MOD Processes for the Fabrication of YBCO-coated Conductors

Abstract

We developed a new precursor solution that consists of copper naphthenate, and yttrium- and barium-trifluoroacetates (advanced TFA solution) that can make the heating rate during calcination increase while maintaining a high J_c. In this paper, we investigated the influence of HF gas generation on the calcination process in order to optimize an advanced TFA-MOD process. The high heating rate and/or low copper content in the starting solution lead to a low J_c. In both cases, a high generation rate of HF gas was observed. Consequently, it is clear that rapid HF gas generation leads to the formation of pores that cause a reduction in J_c values.