DC magnetic field sensing based on the nonlinear magnetoelectric effect in magnetic heterostructures
DC magnetic field sensing based on the nonlinear magnetoelectric effect in magnetic heterostructures
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DOI：
10.1088/0022-3727/49/37/375002
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发表时间：
2016-09-21
影响因子：
3.4
通讯作者：
Shamonin, Mikhail
中科院分区：
文献类型：
--
作者：
Burdin, Dmitrii;Chashin, Dmitrii;Shamonin, Mikhail
近年来，利用铁磁-压电复合层状结构中的磁电效应的高灵敏度磁场传感器已经得到证实。然而，大多数提出的概念是没有用的测量直流磁场，因为压电层的导电性导致传感器的灵敏度在低频率的强烈下降。本文介绍了一种用于直流磁场测量的新型磁电式传感器的工作原理。该传感器采用的非线性效应的电压谐波产生的复合磁电结构的同时施加的强交流磁场和弱直流磁场的影响下进行测量。这种物理效应是由于铁磁层中的磁致伸缩对磁场的非线性依赖性而产生的。制造了一种传感器原型，其包括夹在两层非晶铁磁合金之间的压电纤维换能器。实验研究了磁场范围、频率特性和噪声水平等技术指标。原型显示出2.5 V mT（-1）的响应度，并允许在10 nT至约0.4 mT的范围内测量直流磁场。虽然传感器操作是基于非线性效应，传感器的响应可以在一个广泛的动态范围内延伸超过5个数量级的测量磁场的线性。基本的物理解释，通过一个简化的理论所提出的传感器。磁电传感器的功能、差异和优点与磁通门磁力计相比非常好。考虑了提高传感器性能的途径。
Recently, highly sensitive magnetic field sensors using the magnetoelectric effect in composite ferromagnetic-piezoelectric layered structures have been demonstrated. However, most of the proposed concepts are not useful for measuring dc magnetic fields, because the conductivity of piezoelectric layers results in a strong decline of the sensor's sensitivity at low frequencies. In this paper, a novel functional principle of magnetoelectric sensors for dc magnetic field measurements is described. The sensor employs the nonlinear effect of voltage harmonic generation in a composite magnetoelectric structure under the simultaneous influence of a strong imposed ac magnetic field and a weak dc magnetic field to be measured. This physical effect arises due to the nonlinear dependence of the magnetostriction in the ferromagnetic layer on the magnetic field. A sensor prototype comprising of a piezoelectric fibre transducer sandwiched between two layers of the amorphous ferromagnetic Metglas (R) alloy was fabricated. The specifications regarding the magnetic field range, frequency characteristics, and noise level were studied experimentally. The prototype showed the responsivity of 2.5 V mT(-1) and permitted the measurement of dc magnetic fields in the range of similar to 10 nT to about 0.4 mT. Although sensor operation is based on the nonlinear effect, the sensor response can be made linear with respect to the measured magnetic field in a broad dynamic range extending over 5 orders of magnitude. The underlying physics is explained through a simplified theory for the proposed sensor. The functionality, differences and advantages of the magnetoelectric sensor compare well with fluxgate magnetometers. The ways to enhance the sensor performance are considered.