Metalorganic Deposition of YBCO Films for Second-Generation High-Temperature Superconductor Wires

Metalorganic deposition (MOD) is an attractive process for low-cost, high-rate deposition of YBa2Cu3O7– (YBCO) films on continuous lengths of biaxially textured metallic templates for second-generation (2G) high-temperature superconductor (HTS) wires.MOD of YBCO films involves four steps:precursor synthesis, coating, decomposition, and reaction.The final films must meet stringent requirements, including high critical current, uniformity across the width and along the length of the textured substrate, and excellent mechanical properties.Achieving these properties has required the development of a metalorganic precursor that produces an intermediate BaF2-based film, which in turn is converted to a high-quality YBCO film.Understanding and controlling the deposition of the metalorganic precursor and its conversion to YBCO are critical to reproducibly manufacturing uniform, high-performance, HTS wires required for commercial applications.This article reviews the issues that must be addressed in the use of MOD for low-cost YBCO film fabrication and summarizes the performance of 2G HTS wires prepared by this manufacturing process.