Transport current losses in HoBaCuO-123 coated conductors with a Ni-alloy substrate

AC transport current losses in HoBaCuO-123 tape-shaped coated conductors with ferro-magnetic Ni-alloy substrates were measured as a function of an external DC magnetic field. Influence of ferromagnetism of the substrates on transport current losses in the conductors was investigated. The experimental results were compared with theoretical models given by the Norris equations, and showed significant influence of ferromagnetism of the substrates, when the substrates were not magnetically saturated by an external DC magnetic field. However, when the substrates were saturated, the loss characteristics were similar to those of coated conductors with non-magnetic substrates. The experiments also showed that the influence of the ferromagnetism was strongly dependent of the direction of the external DC magnetic field to the wide face of the tape.