Tailoring the crystallographic orientation of MOD-derived La2Zr2O7 buffer layers for coated conductors

Abstract

Well-textured metal-organic-deposited (MOD) Lanthanum Zirconate (La2Zr2O7, LZO) films were spin-coated on biaxially textured Ni–5at.%W substrates for low cost production of YBa2Cu3O7−δ (YBCO) coated conductors. Control of the crystallographic orientation of LZO buffers is of significance to achieve YBCO films with high current carrying capability by means of the selective MOD-seed layer and annealing conditions. X-ray diffraction analysis indicated that the three-layer LZO films on MOD-seed layer, especially MOD–CeO2, showed a significant improvement in out-of-plane and in-plane textures. The surface analysis revealed a typical dense, cracks-free, and homogenous morphology. 500nm-thick YBCO films epitaxially grown on three-layer LZO buffer layers without seed layer, on seed MOD-Y2O3 and MOD-CeO2 by direct-current sputtering, yielded critical current density (Jc) at 77K of 0.6MA/cm2, 1.2MA/cm2 and 1.4MA/cm2, respectively, exhibiting that the superconducting properties were governed by the crystallographic texture of the underlying buffer layer.