Measuring the Hysteresis Curve of Not-Saturated, High-Coercive Permanent Magnets by Pulsed-Field-Magnetometer

The article describes a procedure, which allows magnetic measurements of not completely saturated magnets with respect to the measuring conditions in an open magnetic circuit. In order to measure the magnetic properties of a new generation of Nd-Fe-B permanent magnets with high coercivity a pulsed field magnetometer is used. The measurement of the hysteresis curve of not fully saturated permanent magnets is performed by a special technique, that consists of an additional measurement and a recalculation of the data. This technique allows observing the actual hysteresis curves for all states of not saturated magnetization. Furthermore, the analysis exhibits that the results of measuring the magnetic properties of high coercive magnets in an `open-loop' have to be discussed separately. Both cases for a not saturated permanent magnet, partially demagnetized and not fully magnetized, are examined.