A novel process for CeO_2 single buffer layer on biaxially textured metal substrates in YBCO coated conductors

摘要

We report a newly developed method, namely the in situ postannealing texture (IPAT) technique, based on a two-step principle to fabricate CeO_2 single buffer layer on biaxially textured Ni-5 at. Percent W substrate by a reactive direct-current sputtering method. The annealing temperature and time dependence of the grain alignment in CeO_2 buffer layers was studied. High-quality CeO_2 layers were achieved at annealing temperatures from 750 to 850 deg C, with annealing times from 10 to 20 rain. Atomic force microscopy revealed, via the novel IPAT method, a continuous, dense, and crack-free surface morphology for CeO_2 thin films with a thickness of up to 300 nm, which act as a sufficiently good single buffer for Yba_2Cu_3O_(7-delta) (YEGG) coated conductors (CCs). The preparation of subsequent YBCO CCs grown on the IPAT-prepared CeO_2 single buffer layers was also investigated.