Thickness Effect on the Structural and Electrical Properties of Sputtered YBCO Coated Conductors

Abstract

In this paper we studied the structural and electrical properties variations with the thickness of YBa 2 Cu 3 O 7 X (YBCO) film. In our experiments, the critical current density (Jc) has a maximum at 1.2 micron rather than monotonically decreased with increasing film thickness. The in-plane and out-plane alignments of the films, measured with X-ray Diffraction Omega-scan and Phi-scan, were poor at the beginning stage of the deposition and then became better as the film thickness increased.The surfaces of different samples also change a lot while films less than 700 nm in thickness. Under optimized deposition conditions, biaxial textured YBCO films have been obtained, with the full width at half maximum being 2.1 and 4.5 for out-of-plane and in-plane orientations respectively, Jc greater than 1.2 MA/cm 2 at 77 K, self field.

Dependencies of microstructure and stress on the thickness of GdBa2Cu3O7 − δ thin films fabricated by RF sputtering

“…They associated the pinholes with stronger oriented grains along the c -axis [14]. Tao et al [15] (by sputtering method, in their Figure seven), Chen et al [16] (by advanced low-fluorine solution method, in their Figure four), and Vermeir et al [17] (by fluorine-free water-based sol–gel method, in their Figure five) also reported a similar pinhole appearance. In another series of experiments for GdBCO films deposited with different temperatures, we find that a higher temperature favors the emergence of pinholes while a lower temperature favors a flat film without pinholes.…”

“…Tao et al [15] reported the J c of YBCO film to be 1.6 × 10 6 A/cm 2 at 77 K and self-field with a thickness of 1.2 μm by sputtering method on buffered Ni-5 at.% W substrates. Tran et al [23] found that the 0.2-μm-thick GdBCO film had the highest J c of 3.8 × 10 6 A/cm 2 and the J c value decreased to 4.2 × 10 5 A/cm 2 as the film thickness increased to 0.55 μm.…”