Fang Xiujie, Ma Danyue, Sun Bowen, Xu Xueping, Quan Wei, Xiao Zhisong, Zhai Yueyang
School of Physics, Beihang University, Beijing 100191, China.
Zhejiang Provincial Key Laboratory of Ultra-Weak Magnetic-Field Space and Applied Technology, Hangzhou Innovation Institute of Beihang University, Hangzhou 310000, China.
Materials (Basel). 2022 Sep 26;15(19):6680. doi: 10.3390/ma15196680.
This study proposes a high-performance magnetic shielding structure composed of MnZn ferrite and mu-metal film. The use of the mu-metal film with a high magnetic permeability restrains the decrease in the magnetic shielding coefficient caused by the magnetic leakage between the gap of magnetic annuli. The 0.1-0.5 mm thickness of mu-metal film prevents the increase of magnetic noise of composite structure. The finite element simulation results show that the magnetic shielding coefficient and magnetic noise are almost unchanged with the increase in the gap width. Compared with conventional ferrite magnetic shields with multiple annuli structures under the gap width of 0.5 mm, the radial shielding coefficient increases by 13.2%, and the magnetic noise decreases by 21%. The axial shielding coefficient increases by 22.3 times. Experiments verify the simulation results of the shielding coefficient of the combined magnetic shield. The shielding coefficient of the combined magnetic shield is 16.5%. It is 91.3% higher than the conventional ferrite magnetic shield. The main difference is observed between the actual and simulated relative permeability of mu-metal films. The combined magnetic shielding proposed in this study is of great significance to further promote the performance of atomic sensors sensitive to magnetic field.
本研究提出了一种由锰锌铁氧体和坡莫合金薄膜组成的高性能磁屏蔽结构。使用具有高磁导率的坡莫合金薄膜可抑制磁环间隙间磁泄漏导致的磁屏蔽系数下降。坡莫合金薄膜0.1 - 0.5毫米的厚度可防止复合结构磁噪声增加。有限元模拟结果表明,随着间隙宽度增加,磁屏蔽系数和磁噪声几乎不变。在间隙宽度为0.5毫米时,与具有多个环形结构的传统铁氧体磁屏蔽相比,径向屏蔽系数提高了13.2%,磁噪声降低了21%。轴向屏蔽系数提高了22.3倍。实验验证了组合磁屏蔽屏蔽系数的模拟结果。组合磁屏蔽的屏蔽系数为16.5%。比传统铁氧体磁屏蔽高91.3%。在坡莫合金薄膜的实际相对磁导率和模拟相对磁导率之间观察到主要差异。本研究提出的组合磁屏蔽对于进一步提升对磁场敏感的原子传感器的性能具有重要意义。