Strong pinning in very fast grown reactive co-evaporated GdBa2Cu3O7 coated conductors

We report on compositional tuning to create excellent field-performance of J(c) in self-doped, GdBa2Cu3O7-y (GdBCO) coated conductors grown by ultrafast reactive co-evaporation. In order to give excess liquid and Gd2O3, the overall compositions were all Ba-poor and Cu-rich compared to GdBCO. The precise composition was found to be critical to the current carrying performance. The most copper-rich composition had an optimum self-field J(c) of 3.2 MA cm(-2). A more Gd-rich composition had the best in-field performance because of the formation of low coherence, splayed Gd2O3 nanoparticles, giving J(c) (77 K, 1 T) of over 1 MA cm(-2) and J(c) (77 K, 5 T) of over 0.1 MA cm(-2). (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.