Magnetization of Ferromagnetic-SC Heterostructures for Trapped Field Low Power Motors

The applicability of bulk based superconducting parts as magnetic elements for small sized motors is limited because the fact that the maximum flux density they can trap depends on the size. Also, the long time stability of the flux trapped in superconducting parts depends on the working interacting field which modifies the magnetization of pellets. In this work, we analyze the magnetic behavior of structures made by an iron yoke and a bulk-based ring around the yoke when subjected to an external and variable magnetic field. The in-field Hall mapping technique is used to determine how the iron improves the maximum trapped magnetic field. The stability of the flux trapped in the structure when a non-aligned external field is applied, and the application to low power motors is discussed.