Magneto-optical investigations of Ag-sheathed Bi-2223 tapes with ferromagnetic shielding

TL;DR

This study uses magneto-optical imaging to analyze how Ni-coated Ag-sheathed Bi-2223 superconducting tapes behave under magnetic fields, revealing differences in flux propagation due to ferromagnetic shielding.

Contribution

It provides experimental visualization of magnetic flux distribution in Bi-2223 tapes with ferromagnetic Ni coating, highlighting effects of magnetic shielding on flux behavior.

Findings

Flux propagation differs in Ni-coated vs. uncoated samples.

Magnetic field distribution varies with temperature and external field.

Ferromagnetic shielding influences flux dynamics in superconducting tapes.

Abstract

An increase in the critical current and suppression of AC losses in superconducting wires and tapes with soft magnetic sheath have been predicted theoretically and confirmed experimentally. In this work we present the results of magneto-optical investigations on a series of Ag-sheathed Bi-2223 tapes with Ni coating. We visualize distributions of magnetic field at increasing external field and different temperatures, demonstrating a difference between the flux propagation in the superconductor with Ni rims and a reference sample without Ni coating.