The Superconducting Properties of Several HTS GdBCO Coated Conductors

The superconducting properties of four high-temperature superconducting (HTS) GdBCO coated conductors (CCs) with GdBCO film thicknesses ranging from 1.04 to 1.65 μm have been analyzed. The crystallinity of the GdBCO superconducting layer showed no significant change as the film thickness increased. The transport critical current (I_c) values exhibited a linear increase with thickness, while the critical current density (J_c) remained consistent despite the increased thickness. The magnetic properties of all HTS GdBCO CCs were investigated using a commercial Quantum Design SQUID-VSM. The lower critical field (H_c1), penetration field (H_p), and irreversibility magnetic field (H_irr) were estimated from their magnetic moment m(H) curves. The temperature dependence of H_c1, H_p, and H_irr was found to be nearly independent of GdBCO film thicknesses. Additionally, the critical current density J_c values were derived from the irreversible magnetic moment Δm(H) data using a modified Bean model. Across all temperatures, the resulting J_c(t) values remained largely unchanged with increasing GdBCO film thickness (t).