Low AC Loss Inkjet-Printed Multifilamentary YBCO Coated Conductors

Impressive performance has been achieved in (RE)Ba₂Cu₃O_7-δ (REBCO) coated conductors, but for many applications, the high cost and ac losses remain prohibitive. Inkjet printing methods combine scalability and low equipment cost with high-resolution patterning, potentially addressing both issues by enabling the production of multifilamentary coated conductors without subtractive processing. The successful production of multifilamentary superconducting YBa₂Cu₃O_7-δ (YBCO) structures by inkjet printing of a low-fluorine YBCO precursor solution on SS/ABAD-YSZ/CZO substrates is reported. Two approaches have been developed. In the first method, YBCO filaments were directly deposited on the buffered substrate by piezoelectric printing; and in the second approach, CeO₂ tracks were first printed to pattern a subsequently overprinted YBCO film, creating a multifilamentary structure by an inverse technique. Scanning Hall probe measurements have been used to compare the filamentary structures and critical currents achieved by both methods, and a J_c of up to 3 MA cm^-2 has been obtained at 77 K. For the inverse printing approach, the ac hysteresis losses have been also measured and compared with theoretical models.