Study on the Magnetic Noise Characteristics of Amorphous and Nanocrystalline Inner Magnetic Shield Layers of SERF Co-Magnetometer

Abstract

With the widespread use of magneto-sensitive elements, magnetic shields are an important part of electronic equipment, ultra-sensitive atomic sensors, and in basic physics experiments. Particularly in Spin-exchange relaxation-free (SERF) co-magnetometers, the magnetic shield is an important component for maintaining the SERF state. However, the inherent noise of magnetic shield materials is an important factor limiting the measurement sensitivity and accuracy of SERF co-magnetometers. In this paper, both amorphous and nanocrystalline materials were designed and applied as the innermost magnetic shield of an SERF co-magnetometer. Magnetic noise characteristics of different amorphous and nanocrystalline materials used as the internal magnetic shielding layer of the magnetic shielding system were analyzed. In addition, the effects on magnetic noise due to adding aluminum to amorphous and nanocrystalline materials were studied. The experimental results show that compared with an amorphous material, a nanocrystalline material as the inner magnetic shield layer can effectively reduce the magnetic noise and improve the sensitivity and precision of the rotation measurement. Nanocrystalline material is very promising for inner shield composition in SERF co-magnetometers. Furthermore, its ultra-thin structure and low cost have significant application value in the miniaturization of SERF co-magnetometers.

Special Issue: “Soft Magnetic Materials and Their Applications”

“…Particularly in spin-exchange relaxation-free (SERF) co-magnetometers, the magnetic shield is an important component for maintaining the SERF state. Liu et al applied different amorphous and nanocrystalline materials as the innermost magnetic shielding layers of an SERF co-magnetometer and analyzed their magnetic noise characteristics [ 17 ]. The experimental results show that compared with an amorphous material, using a nanocrystalline material as the inner magnetic shield layer can effectively reduce the magnetic noise and improve the sensitivity and precision of the rotation measurement.…”

Study on the magnetic shielding properties of nanocrystalline strips under bending stress

“…Nanocrystalline alloys are the new generation of soft magnetic materials with high permeability and high saturation magnetic induction. They are lighter and thinner (usually around 18 ∼ 25 μm) than permalloy, and so nanocrystalline alloys have a broad application prospect in reducing the cost of MSR preparation and miniaturization [8,9]. However, the magnetic properties of nanocrystalline materials are inevitably affected by mechanical stresses during MSR assembly and use.…”

Test and Analysis of High-Permeability Material’s Microstructure in Magnetic Shielding Device

“…The magnetic shielding device is used to reduce the ambient magnetic interfering signals (including the geomagnetic field and the ambient magnetic field fluctuations) significantly, by which, an extreme weak, high uniform, small time drifts, and low noisy magnetic field could be obtained [1][2][3]. The demands for the magnetic shielding device come from a variety of fields such as fundamental physics [4,5], biomedical science [6,7], underground survey [8], space research [9], and industrial applications [10].…”