Growth of all-chemical high critical current YBa2Cu3O7−δ thick films and coated conductors

Supercond. Sci. Technol. 32 015004

Abstract: The achievement of high critical currents in ‘all-chemical’ YBa₂Cu₃O_7−δ thick films from low cost and versatile chemical solution deposition (CSD) methodology is still an open issue. Here we report a study of the nucleation and growth conditions to achieve YBa₂Cu₃O_7−δ films in excess of 1 micron using single pass inkjet printing or multideposition of low-fluorine metalorganic precursors. Growth conditions of thick YBa₂Cu₃O_7−δ layers are first investigated on LaAlO₃, where there is no interfacial chemical reactivity. The second architecture investigated is an ‘all-chemical’ ^CSDCe_0.9Zr_0.1O₂(CZO)/YSZ multilayer on single crystal substrates which serves as model system for coated conductors. Finally, the ‘all-chemical’ coated conductor architecture ^CSDYBa₂Cu₃O₇/^CSDCZO/^ABADYSZ/stainless steel, where ABAD stands for alternating beam assisted deposition, is investigated. The nucleation conditions of YBa₂Cu₃O_7−δ films on top of CΖΟ cap layers have been selected to minimize the formation of the BaCeO₃ phase at the interface. We demonstrate that by combining the use of Ag additives in the starting YBCO solution and processing conditions leading to low supersaturation (high water pressure and low temperature) we can achieve ~1 μm thick YBa₂Cu₃O_7−δ films and coated conductors with high critical currents of  = 390 and 100 A/cm-w, respectively, at 77 K and self-field. The achieved control of the interfacial reactivity with CeO₂ cap layers opens a route for further increasing film thickness and critical currents in ‘all-chemical’ YBa₂Cu₃O_7−δ coated conductors.