Possible new single-buffer layers for YBa₂Cu₃O_7−y coated conductors prepared by chemical solution deposition

New single-buffer layers of YBiO₃ and SmBiO₃ have been proposed for YBa₂Cu₃O_7−y (YBCO) and SmBa₂Cu₃O_7−y coated conductors. Highly c-axis oriented YBiO₃ and SmBiO₃ buffer layers have been deposited on single-crystal LaAlO₃ and SrTiO₃, respectively, by a low-cost chemical solution deposition method in a temperature range as low as 730 to 800 °C in air. Precursor solution of yttrium nitrate, samarium nitrate, and bismuth nitrate has been deposited using spin coating and heat treated in air in a single stage to yield textured YBiO₃ and SmBiO₃ buffers. A very dense, smooth, pinhole-free, and crack-free morphology has been observed for both buffers. Dense, homogeneous, and epitaxially grown YBCO film with thickness about 300 nm has been obtained on YBiO₃ buffer with onset critical temperature 90 K and J_c (77 K, self-field) over 3 MA/cm². These results offer an effective alternative to prepare desirable buffer layer(s) for YBCO-coated conductors.