MOCVD of Heavily-Doped 25 mol.% Zr-Added (Gd, Y)Ba2Cu3O7-δ Coated Conductors

Abstract

The requirements for achieving critical current densities above 3.5 MA cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–2</sup> at 77 K, 0 T in heavily-doped Zr-added REBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7−δ</sub> (REBCO and RE = Gd, Y) coated conductors were previously determined. In this work, the effects of deposition temperature and oxygen partial pressure on the microstructure and the texture of (Gd, Y)Ba <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7-δ</sub> coated conductors with Zr content of 25 mol.%, grown by reel-to-reel metal organic chemical vapor deposition have been investigated. The results shows that the in-plane and out-of-plane texture quality of (Gd, Y)BCO coated conductors depend strongly on deposition temperature and oxygen partial pressure. It was also noticed that as (Gd, Y)BCO coated conductors become more Ba-rich, the overall in-plane texture quality deteriorates. The critical current density at 77 K, 0 T in 25 mol.% Zr-added (Gd, Y)BCO coated conductors is found to be sensitive to the (Ba+Zr)/Cu content in the films.