Measurement of Remanent Coercivity of Soft Magnetic Materials by Atomic Magnetometer

The experimental equipment and method for measuring the remanent coercivity of soft magnetic materials by a pump-probe rubidium atomic magnetometer are reported. The soft magnetic sample is magnetized and demagnetized by scanning the pulse current applied to the magnetization coil which is placed in the magnetic shielding cylinder. The remanent magnetization of the soft magnetic sample is monitored by a pump-probe rubidium atomic magnetometer, and the average remanent coercivity of the sample is calculated by the remanent magnetization hysteresis loops. The remanent coercivity of a Permalloy strip sample is measured by the experimental device and method proposed in this paper, the average remanent coercivity is 1.706 mT, and the reproducibility of ten repeated measurements expressed as a relative standard deviation is 0.05%. The method of measuring the remanent coercivity by using the pump-probe atomic magnetometer has the advantages of no zero-point drift, good repeatability, fast measurement speed and in-situ measurement, and has the potential to develop magnetic measuring equipment suitable for the field of environmental magnetism in the future.