Advanced TFA-MOD process of high critical current YBCO films for coated conductors

Fabrication of YBCO Film Using a New Copper Precursor by Chemical Solution Method

“…The result is close to the decomposition behavior of all-TFA YBCO gel reported by Dawley et al [12] and Yoo et al [9]. This abrupt weight change is related to the amount of HF and COF 2 gas generation [4,16]. As result of this, the humid gas and the low heating rate were used to suppress the sublimation and to acquire the crackfree precursor films [3].…”

“…The J c decreases with increasing the heating rate from 3 K/min to 10 K/min. This trend is similar to that of the advanced TFA-MOD YBCO reported by Tokunaga et al [4]. As the heating rate increases, the J c reduces from a maximum value (1.7 MA/cm 2 ) at 3 K/min.…”

“…Bhuiyan et al developed a modified TFA-MOD precursor route, with copper sulfate as fluorine free precursor, to deposit thick YBCO films that requires less than one-fifth of the pyrolysis time compared to the traditional TFA-MOD approach [6]. The advanced TFA-MOD developed by SRL-ISTEC provided YBCO films with high critical current density [4]. They investigated the effects of calcinations conditions on microstructures and J c properties of YBCO films by using the copper naphthenate as the precursor [7,8].…”

“…A modified precursor solution is therefore required for a fast pyrolysis process. The reduction of fluorine content in the precursor or addition of a high-boiling-point solvent could contribute to the formation of smooth and homogeneous surfaces of precursor films during the fast pyrolysis step [4,5]. Some efforts have already been made to enhance the processing by modification of a precursor solution.…”

High-<TEX>$I_c$</TEX> single-coat YBCO films prepared by the MOD process

“…By employing a fluorine-reduced precursor solution, the pyrolysis stage could be greatly shortened within 3 h [8,9]. The cracks generated during the pyrolysis stage made it hard to produce high-I c YBCO films since they were maintained after the firing stage.…”