Liquid Phase Stabilization and Superconducting Properties by Adding Ag to SmBa₂Cu₃O_y Coated Conductors Fabricated by Vapor-Liquid-Solid Growth Technique

Abstract

It is necessary to increase the deposition rate in order to reduce the production cost of REBCO coated conductors. The Vapor-Liquid-Solid (VLS) growth technique is a method capable of fabricating a thin film with high-deposition rate and good crystalline orientation owing to a crystal growth through a liquid phase. Increase of oxygen partial pressure (P_O2) during the deposition is effective on increase of the deposition rate. However, since melting point of the liquid phase becomes higher with increasing P_O2, it is difficult to fabricate a film at the high P_O2. In this study, we tried to lower melting point of the liquid phase by adding Ag in the VLS growth technique. By adding Ag to the liquid phase, VLS growth mode in a stable liquid phase became possible even in the high P_O2. As a result, we achieved fabrication of a film at a high deposition rate of 26.0 nm/sec with good crystalline orientation and the critical current density (J_c) of the film was improved.