Raman scattering spectroscopy of Nd1+xBa2−xCu3O7coated conductors grown by pulsed laser deposition

We analyzed Nd1+x Ba2−x Cu3O7 (NdBCO) coated conductors grown at various substrate temperatures by using Raman spectroscopy. Epitaxial NdBCO films were deposited on ion beam assisted deposition yttrium stabilized zirconia (IBAD-YSZ) templates by pulsed laser deposition. Raman scattering spectroscopy shows that the NdBCO film grown at a relatively low substrate temperature of 750 ◦ C contains some a-axis oriented grains as well as c-axis oriented grains and an excess cation disorder between Nd 3+ ions and Ba 2+ sites, which result in degradation of superconducting properties with critical temperature (Tc )o f∼83 K and critical current density (Jc )o f less than 1 MA cm −2 at 77 K and self-field. The samples grown at higher temperatures ranging from 775 to 800 ◦ C are found to have strong c-axis orientation with little cation disorder, and subsequently excellent superconducting properties with Tc of 88–90 K and Jc of 1.2–1. 8M A cm −2 at 77 K and self-field. (Some figures in this article are in colour only in the electronic version)