Study of Compositional and Artificial Pinning Effects on Superconductivity of Pulsed-Laser Deposited Gd-123 Films for Coated Conductor Applications

Critical temperature (T_c), critical current density (J_c) and flux pinning characteristics of superconducting films are crucially influenced by their chemical composition. We studied the effect of small composition variations on superconductivity of GdBa₂Cu₃O_7-x (Gd-123) films grown by pulsed laser deposition (PLD) technique. Several pathways to control the composition of Gd-123 films were studied: variation of clearance between edge of laser plume and substrate surface, utilization of off-stoichiometric target compositions and addition of GdZrO₃. Positive effect of Ba-deficiency on superconductivity of Gd-123 films was shown. Comparative study of Gd-123 and Y-123 films on CeO₂ capped Gd₂Zr₂O₇ (GZO) buffered Hastelloy tapes confirmed the advantage of Gd-based compositions for application in magnetic fields and their high potential for fabrication of long-length coated conductors.