YBa₂Cu₃O_x Thin Films with Yttria Stabilized Zirconia Buffer Layer on Metal Substrate by Liquid Source Chemical Vapor Deposition Using Tetrahydrofuran Solution of β-Diketonates

Abstract

Textured YBa 2 Cu 3 O x (YBCO) thin films with c -axis orientation on Ni-based metal substrate with yttria stabilized zirconia (YSZ) and Pt buffer layers were formed by liquid source chemical vapor deposition (LS-CVD) using tetrahydrofuran (THF) solution of β-diketonates. The YSZ buffer layer with a -axis orientation was formed by the similar LS-CVD on prebuffer layers of amorphous YSZ and Pt deposited by sputtering at room temperature. The CVD-YSZ buffer layer was mechanically polished before the deposition of YBCO. By transmission electron microscopy (TEM) and analytical electron microscopy (AEM), it was ascertained that YBCO and YSZ layers had platelike and column-shaped grains, respectively. An intermetallic compound of the Pt-Ni-Cr system was produced in the vicinity between the YSZ layer and metal substrate. The critical temperature ( T c ) of 91 K and the transport critical current densities ( J c ) of 1.4×10 5 A/cm 2 at 77 K, zero field, and 2.0×10 4 A/cm 2 at 1.5 T were achieved.