Magnetically exchange coupled MnBi/FeCo thin film composites with enhanced maximum energy products

MnBi/FeCo thin film composites are synthesized by magnetron sputtering, the physical and crystal structures are confirmed by SEM and XRD. The magnetic properties are characterized by VSM. When the FeCo layer thickness is 2 and 4 nm, magnetic exchange coupling between MnBi and FeCo is demonstrated by enhanced maximum energy product in MnBi/FeCo thin films from the single hard phase of MnBi. When the FeCo thickness is further increased to 6 nm, the exchange coupling between MnBi and FeCo is destroyed in MnBi/FeCo thin films. This research explored a possible way to increase the maximum energy product of MnBi thin films.