The epitaxial growth of BaSnO3 buffer layer on IBAD-MgO template and its effects on GdBa2Cu3O7−δ film: A preliminary study

We report a successful fabrication of c-axis oriented GdBa2Cu3O7−δ (GdBCO) films on the BaSnO3 (BSO) buffer layers on ion-beam assisted deposition (IBAD)-MgO template by pulsed-laser deposition (PLD). The (0 0 l) growth and in-plane textures of BSO buffer layers were found sensitive to the substrate temperature (Ts). With increasing the BSO layer thickness up to ∼165 nm, in-plane texture (Δϕ ∼ 6.2°) of BSO layers was almost unaltered while completely c-axis oriented BSO layers were obtainable from samples with the thickness below ∼45 nm. On the BSO buffer layers showing in-plane texture of 6.2° and RMS surface roughness of ∼8.6 nm, GdBCO films were deposited at 780–800 °C. All GdBCO films exhibited Δϕ values of 4.6–4.7°, Tc,zero of ∼91 K, and critical current density (Jc) over 1 MA/cm2 at 77 K in a self-field. The highest Jc value of 1.82 MA/cm2 (Ic of 51 A/cm-width) was achieved from the GdBCO film deposited at Ts of 790 °C. These results support that BSO can be a promising buffer layer on the IBAD-MgO template for obtaining high-Jc GdBCO coated conductors.