Synthesis of YGBCO Superconducting Coatings by Metal Organic Chemical Vapor Deposition in Narrow Rectangular-Wedge Reactor

The Y_0.5Gd_0.5Ba₂Cu₃O_7-x (YGBCO) superconducting coatings were synthesized by metal organic chemical vapor deposition (MOCVD) in a lab-built reactor with a narrow rectangular wedge deposition zone, comprising two tilted Cu-plates (300 mm×11 mm) inside the rectangular vacuum chamber to accelerate the velocity of metal organic vapor.The influence of the rectangular wedge reactor on the properties of the YGBCO coatings was investigated with X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy and critical current density (J_c) measurement.The results show that the rectangular wedge reactor had a major impact.To be specific, the compact, fairly uniform and single Y123-phased YGBCO coatings, 280 nm in thickness and grown in a 200 mm long reactor, had a Jc up to 3.5 MA/cm² (measured at 77 K and 0 T).We suggest that the marrow rectangular wedge reactor be capable of rapidly and continuously growing high quality YBCO superconducting tape by MOCVD.