Characteristics of High- J GdBCO Coated Conductors Fabricated by the RCE-DR Process

• Published in: IEEE transactions on applied superconductivity 2013-06, Vol.23 (3), p.8001004-8001004
• Main Authors: Soon-Mi Choi, Jung-Woo Lee, Gang-Hwan Shin, Jae-Hun Lee, Gye-Won Hong, Seung-Hyun Moon, Sang-Im Yoo
• Format: Article
• Language: English
• Subjects: Conductors; Flux pinning; GdBCO CCs; hbox{Gd}_{2}\hbox{O}_{3} particles; Magnetic fields; Moon; RCE-DR process; TEM; X-ray scattering
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2012.2234814

We report the characteristics of GdBa 2 Cu 3 O 7-δ (GdBCO) coated conductors (CCs) on LaMnO 3 (LMO)-buffered IBAD MgO template, produced by the Reactive Co-Evaporation Deposition & Reaction (RCE-DR) process. The transport and magnetic critical current density ( J c ) values of GdBCO CC samples were 3.7 and 2.92 MA/cm 2 at 77 K in self-field for B // c , respectively. Analyses by transmission electron microscopy revealed that a large amount of elongated round Gd 2 O 3 particles with 70-150 nm size and a small amount of the Cu-O phase were trapped in the GdBCO matrix, and a thick layer of the Cu-O phase was also found on the top surface of the GdBCO film, suggesting that the GdBCO film must be grown by the peritectic recombination reaction between Gd 2 O 3 and a liquid phase. While both the GdBCO film and some Gd 2 O 3 particles grown on the LMO-buffer layer were biaxially textured, the Gd 2 O 3 particles fully trapped in the GdBCO matrix were randomly oriented. The GdBCO film by RCE-DR possessed slightly degraded value of exponent α ~ 0.84 in the power-law relationship J c ~ H - a and rather large anisotropy in field-orientation dependence of J c , J c (θ), and thus refinement of Gd 2 O 3 particles may be required for stronger flux pinning.