AC Loss Filamentization of 2G HTS Tapes by Buffer Stack Removal

Abstract

Filamentization of 2G-HTS tapes provides a means for significant reduction of magnetization AC losses in coated conductors. Photolithography followed by dry etching is one of the approaches to `top-down' filamentization of REBCO (RE=rare earth) and shunt layers. Some of the issues associated with this approach include REBCO undercuts, as well as the complexity and cost of the process. In this work, we present results on a study aimed at developing an alternative, `bottom-up' filamentization technique that is free of undercuts, has low cost, high throughput and is readily scalable. Here, the buffer tape is striated by mechanically removing thin stripes of the buffer stack, followed by the REBCO Metal Organic Chemical Vapor Deposition (MOCVD) process. We couple this technique with a low cost deposition of the silver shunt layer using electrodeposition instead of sputtering and study the conditions for selective electrodeposition on the superconducting filaments.