Thin YBa₂Cu₃O_7-δpatterns by Chemical Solution Processing using Ink-Jet Printing

Abstract

In this paper, we present ink-jet printing as an attractive alternative to lithography and etching methods for the development of multi-filamentary YBa 2 Cu 3 O 7-δ coated conductors. Our research is mainly focused on the study of the influence of rheological parameters on the printability of water-based inks in order to produce superconducting patterns on SrTiO 3 and CeO 2 -La 2 Zr 2 O 7 -Ni5at%W substrates. An aqueous YBCO precursor ink with a total metal ion concentration of 1.1 mol/L with a viscosity of 6.79 mPa s and a surface tension of 67.9 mN/m is developed. Its printing behavior using several ink-jet printing devices is verified using a camera with strobed illumination to quantify droplet velocity and volume. After optimization of the deposition parameters, YBCO tracks with different dimensions could be printed on both types of substrates. Their shape and dimensions were determined using optical microscopy and noncontact profilometry, showing 100-200 nm thick and 40-200 µm wide tracks. Finally, resistivity measurements were performed on the widest tracks on SrTiO 3 showing a clear drop in the resistivity starting from 88.6 K with a ∆T c of 1.4 K.

Ink-jet printing of SrTiO3buffer layers from aqueous solutions

“…For our ethanol-modified solution, a contact angle of 12°was found on the cleaned LAO substrates. The theoretical footprint d con of the drop upon impact can then be estimated by the following equation [24,32]: In order to obtain STO films with thicknesses over 100 nm, drop spacings of 0.05 mm in both x and y direction were used, which is clearly below the minimum spacing necessary to achieve stable line formation. To verify whether this solution is suitable for deposition on technical Ni-W substrates, the contact angle of the ethanol-modified STO ink was measured.…”