Observation of magnetic fields due to persistent currents in a ring made of a Y1Ba2Cu3O7-δ coated conductor

Abstract

A ring comprising a coated conductor was fabricated. First, the two ends of a biaxially textured Ni tape were connected by means of the atomic diffusion bonding technique. Then buffer layers and a YBCO film were deposited on the ring. All the films were well textured as confirmed by XRD pole figures. The B-H loops, where B and H are the magnetic field at the centre of the ring and the applied field, respectively, were measured as a function of temperature. The persistent current density (Jc) flowing circularly was estimated from the remanent field of B. In the range of temperatures from 72 to 20 K, Jc changed from 0 to 2×105 A cm-2.