Growth of all-chemical high critical current YBa₂Cu₃O_7−δ thick films and coated conductors

Abstract

The achievement of high critical currents in ‘all-chemical’ YBa2Cu3O7−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 YBa2Cu3O7−δ films in excess of 1 micron using single pass inkjet printing or multideposition of low-fluorine metalorganic precursors. Growth conditions of thick YBa2Cu3O7−δ layers are first investigated on LaAlO3, where there is no interfacial chemical reactivity. The second architecture investigated is an ‘all-chemical’ CSDCe0.9Zr0.1O2(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 YBa2Cu3O7−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 YBa2Cu3O7−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’ YBa2Cu3O7−δ coated conductors.

Accelerated growth by flash heating of high critical current trifluoroacetate solution derived epitaxial superconducting YBa2Cu3O7 films

“…The nanostrain of the FH films, on the other hand, show a significant increase, as compared to the CTA films, reaching e = 0.25% instead of e = 0.11%. 24,55,56 This enhanced values of nanostrain in pristine FH films appear to be similar to those observed in nanocomposite YBCO thin films grown by CTA where a high density of intergrowths is usually observed. 24,56 To investigate the microstructure of pristine FH YBCO films we obtained cross sectional TEM images and compared them with those obtained for films grown by CTA.…”

“…6(d) and (e) where it is appreciated that the films show a negligible porosity and a strong grain connectivity, similarly to optimal CTA films. 5,55 The lattice and texture quality of the c-axis oriented films grown at 750 1C was evaluated by measuring the FWHM of o-scan ((005) peak) and f-scan ((103) peak), c parameter and nanostrain. The c parameter was B11.691 AE 0.010 Å, while Do = 0.621 and Df = 1.291, revealing therefore a good out-of-plane and in-plane texture quality, similar to that observed in CTA films.…”

Superconducting HfO2-YBa2Cu3O7−δ Nanocomposite Films Deposited Using Ink-Jet Printing of Colloidal Solutions

“…This means that cleaning the nozzle regularly is necessary to avoid nozzle blocking. To prevent this cleaning step during the printing session, methanol is replaced with 1-butanol as the solvent in the solutions to increase the vapor pressure and to decrease the evaporation rate [34]. Here, we show the possibility of generating a highly reproducible jettability of colloidal 1-butanol-based YBCO inks without the introduction of any additives in contrast to the YBCO inks of Obradors et al [35], where additives, such as polymer compounds, were introduced.…”

“…Apart from the explained benefits of the nanocrystal addition as artificial pinning centers, this can also be achieved by increasing the superconducting layer thickness. One possibility for increasing the thickness is through ink-jet printing multi-deposition [34]. However, in order to achieve proper jetting ( Figure 1A), fluid properties, such as viscosity, density, and surface tension, must be taken into consideration.…”

Enhancement of Critical Current Density by Establishing a YBa2Cu3O7−x/LaAlO3/YBa2Cu3O7−x Quasi-Trilayer Architecture Using the Sol-Gel Method

“…YBa 2 Cu 3 O 7−x (YBCO)-coated conductors with high current-carrying capacity at liquid nitrogen temperature are currently thought to be the best candidates for power application 1 [1][2][3][4][5]. It is well known, however, that the critical current density (J c ) of YBCO-coated conductors or films decay exponentially with an applied magnetic field [6][7][8].…”