Ultrathin tapes of magnetic alloys with rectangular hysteresis loops

The principal soft magnetic alloys have been rolled to thicknesses between 1/8 and 1 mil. Magnetic properties of toroidal cores wound from ultrathin tapes were studied using d-c magnetization. Even though the coercive force tends to increase with reduced thickness, the coercivity of ultrathin metal tapes is usually lower than that of ferrites or powdered metals. Relatively rectangular d-c hysteresis loops were obtained in three of four alloys investigated.