Growth of High-Performance Thick Film REBCO Tapes Using Advanced MOCVD

Abstract

An Advanced Metal Organic Chemical Vapor Deposition MOCVD (A-MOCVD) reactor has been used to deposit 4+-μm-thick undoped (Gd,Y)BaCuO tapes in a single pass, with consistent critical current above 1400 A/12 mm and critical current density above 2.6 MA/cm2 at 77 K, 0 T. The highest self-field critical current over 1660 A/12 mm and critical current density of 3.3 MA/cm2 are among the best values ever reported in 4+-μm-thick REBCO films. Also, A-MOCVD reactor has been used to grow over 4.5-μm-thick, 5 mol% Zr-doped REBCO films, with ∼45% precursor-to-film conversion efficiency, which is more than four times higher than that achieved in conventional MOCVD reactors. Excellent in-plane and out-of-plane texture values below 2.35° and 1.25°, respectively, have been achieved. Onset critical temperature (Tc) is in the range of 92.5-93.5 K and transition width (ΔTc) is below 1 K. This remarkable demonstration of growth of 4+-μm-thick doped (Gd,Y)BaCuO films with double deposition rate, 4× improvement in precursor-to-film conversion efficiency, and excellent critical current makes A-MOCVD an attractive approach for the manufacturing of low-cost, high-performance superconductor tapes.