Textured Buffer Layer for the Growth of High Temperature Superconductor Thin Films on Polycrystalline Substrates

Period of Performance: 05/01/1998 - 05/01/2000


Phase 2 SBIR

Recipient Firm

Universal Energy Systems, Inc.
Dayton, OH 45432
Principal Investigator


High current carrying tapes for various commercial and military applications can be fabricated by using a coating of high-temperature superconductor such as Yba2Cu3O7 (YBCO) on a suitable metallic tape. For example, a power converter operating at cryogenic temperatures requires high critical current (Jc) superconducting films on Ni-alloy tape. It has been shown, however that YBCO films deposited directly on these substrate materials exhibit poor superconducting properties at liquid nitrogen temperature because of contamination with diffusing species from the surface. A diffusion barrier of textured yttria-stabilized zirconia (YSZ) is needed to grow high Jc YBCO thin films. UES has demonstrated the feasibility of a modified magnetron sputter deposition method for the growth of textured YSZ films on Ni-alloys in Phase I using small tapes. In Phase II, UES proposes to further optimize the process parameters and develop a pilot production process for depositing textured YSZ, and subsequently with YBCO, onto polycrystalline Ni-alloy tape. A reel-to-reel fiber coating system equipped with three cylindrical sputter guns in a available at UES for this scale-up. The system will be modified to achieve the desired goal.