Polymer-assisted chemical solution deposition of high-quality La_2Zr_2O_7 buffer layer applied to low-cost YBCO-coated conductors

摘要

Through a simple and low-cost way to gain the precursor solution, high-quality La_2Zr_2O_7 (LZO) buffer layers approximately 300 nm thick only by one single coating were successfully deposited on the textured Ni-5at%W alloy substrates using an independently developed new method of polymer-assisted chemical solution deposition (PA-CSD) with and without Y_2O_3 seed layer. Highly epitaxial YBa_7Cu_3O_(7-x) (YBCO) thin film with thickness of 500 nm is managed to be deposited on LZO/Y_2O_3/ NiW. A study was made on the buffers and YBCO films with XRD, AFM, FIB-SEM, ESEM, and through superconducting critical temperature (T_c) analyses, and it was found that the Y_2O_3 seed layer had a good effect in improving the c-axis texture for the performance of LZO thin films. More importantly, the value of the self-field critical current density (J_c) of YBCO film on LZO/Y_2O_3/NiW architecture was 1.6 MA/cm~2 at 77 K. Our results indicated that the low-cost and effective way to develop high-performance YBCO-coated conductors on the basis of high-quality LZO buffer layer were suitable candidates.