A pulsed field magnetometer for the characterization of hard magnetic materials

A pulsed-field magnetometer is described that can be used for measuring the hysteresis of hard magnetic materials and also for determining the anisotropy field. The magnetometer operates at room temperature with a maximum field of approximately 12 MA/m. Special emphasis was given to the analysis of the measuring system. The conditions for optimizing a single-layer pick-up coil are calculated. For elliptically shaped particles, the signal is no longer proportional to the mass of the particle. The sensitivity of a single-layer coil increases first with the number of turns of wire (N), saturating for larger N values. The most sensitive coil is achieved when N is equal to the diameter of the wire used. The pick-up signal is calculated for samples with spherical, cylindrical, and elliptical shapes.