Fabrication of High Current YBa<sub>2< /sub>Cu_{3</ sub>O(sub>7-y}) Coated Conductors Using Rolling-Assisted Biaxially Textured Substrates

摘要

High critical current YBa&amp;lt;sub&amp;gt ;2&amp;lt;/sub&amp;gt ;Cu&amp;lt;sub&amp;gt ;3&amp;lt;/sub& amp;amp;gt;O& amp;lt;sub&amp;gt;7- y&amp;lt;/sub&amp;gt; (referred to as YBCO) coated conductors were fabricated with a layer sequence of YBCO/YSZ/CeO&amp;lt;sub&a mp;amp;gt;2&amp; lt;/sub&amp;gt;/Ni. The cube (100) texture in the starting Ni substrates was obtained by cold rolling followed by recrystallization. A thin CeO&amp;lt; sub&amp;gt;2& amp;lt;/sub&amp;gt; (Cerium Oxide) layer with a thickness of 100-200 was grown epitaxially on the biaxially textured-Ni substrates using an e-beam evaporation technique. This was followed by the growth of a thick (&lt;= 0.77 m) YSZ (Yttria Stabilized Zirconia) layer using either e-beam evaporation or rf magnetron sputtering. The e-beam CeO&lt; sub&gt;2&lt;/sub&gt; film had a dense microstructure. The microstructure of the e- beam YSZ film was porous whereas the sputtered YSZ film was dense. The YBCO films were grown by pulsed laser deposition on both e-beam and sputtered YSZ layers. A transport critical current density of ; 1 x l0&lt;sup& gt;6&lt;/sup&gt; A/cm&lt;sup& gt;2&lt;/sup&gt; at 77 K was obtained for ; 0.8 m thick YBCO Rims on both YSZ surfaces in zero field. To demonstrate the quality and compatibility of the e-beam CeO₂ layers; YBCO films were also grown on CeO< sub>2</sub>-buffered YSZ (100) single crystal substrates using e-beam co- evaporated Y-BaF₂-Cu precursors followed by a post-annealing process. A transport critical current density of over 1 x lO^{6< /sup>A/cm< sup>2} at 77 K was obtained on a ; 0.3 m thick YBCO film in zero field.