Application of atomic magnetometer based on nonlinear magneto-optical rotation in soft magnetic materials testing

A new application in measuring the coercivity of a soft magnetic material (nanocrystalline alloy, lk107) by atomic magnetometer based on pump-probe nonlinear magneto-optical rotation is proposed. The magnetization states of the soft magnetic sample magnetized or demagnetized by a pulse current are successfully measured after the magnetizing current being closed. The hysteresis loops with good repeatability are obtained, and the reproducibility of the coercivity values is expressed by the relative standard deviation of 0.8 %. The method and design is good to extend the application of this NMOR atomic magnetometer. Additional applications and future improvements are also discussed.