Selvamanickam, Venkat2018-11-262018-11-26August 2012013-08August 201http://hdl.handle.net/10657/3397In this thesis the critical currents (Ic), structural properties and composition variations of Zr-doped (Gd,Y)Ba2Cu3Ox (GdYBCO) superconducting tapes fabricated by metal organic chemical vapor deposition (MOCVD) were studied. By a modified MOCVD process, the self-field critical currents at 77K of GdYBCO with high Zr doping levels have been enhanced significantly. The in-field performances of critical currents of GdYBCO tapes with Zr-doping levels of 7.5-30 at.% were investigated up to 5 T over a temperature range of 40 K – 77 K. The tape with 20% Zr doping is found to have the highest minimum critical currents and the highest critical currents in orientation of the field perpendicular to the c-axis (H||c) over a wide range of temperatures and magnetic fields. The electromagnetic properties have been related to the microstructure changes. For finding out the optimal film composition with the best in-field performance at 30K, 3T, the influence of composition on in-field performance has also been studied.application/pdfengThe author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).High temperature superconductorMOCVDCoated conductorsFlux pinningMicrostructureComposition2018-11-26Thesisborn digital