DyBa₂Cu₃O_7−<i>x</i>superconducting coated conductors with critical currents exceeding 1000 A cm⁻¹

Abstract

DyBa2Cu3O7−x (DyBCO) films with MgO buffer layers were grown on Hastelloy substrates by inclined substrate deposition (ISD). An almost linear increase of the critical current with the DyBCO film thickness was observed. A maximum critical current of 1018 A cm−1 was measured for a DyBCO film with 5.9 μm thickness, yielding a critical current density of 1.7 MA cm−2 at 77 K and self-field. Transmission electron microscopy (TEM) yielded highly biaxially textured DyBCO films at all thicknesses and, thus, no significant decrease of the critical current density occurs with the film thickness. ISD yields a non-zero component of the growth direction parallel to the DyBCO (a, b)-plane since the DyBCO grows on a faceted MgO surface and avoids a-axis growth. Therefore, the ISD technology offers a unique possibility to overcome thickness limitations in coated conductor technology.