A new system for local area measurements in a pulsed field magnetometer

This paper describes a new measuring system to perform local area magnetization measurements on the surface of a magnetic sample in a pulsed field magnetometer at room temperature. A commercial point pick-up coil is used to detect the induction signal along the radius of samples with cylindrical or disc shapes. The relationship between the induced voltage and the sample geometry is treated and a calibration procedure is proposed to obtain the magnetization values in physical units for the case when the point pick-up coil is at the centre of the sample. The local demagnetizing factor is obtained using the measurement of the local anisotropy field applying the single-point detection (SPD) technique. The measurement of this SPD singularity detected in the transverse reversible susceptibility, using a sample with cubic geometry, is demonstrated for the first time in this type of magnetometer. The application of the system for the investigation of commercial permanent magnets is illustrated, and the advantages and disadvantages are discussed.