Sensitivity and Noise Evaluation of a Bonded Magneto(elasto)Electric Laminated Sensor Based on In-plane Magneto-capacitance Effect for Quasi-static Magnetic Field Sensing

Xin Zhuang (1) , Marc Lam Chok Sing (1) , Christophe Dolabdjian (1) , Yanping Wang (2) , Peter Finkel (3) , Jiefang Li (2) , Dwight Viehland (2)

1 Equipe Electronique - Laboratoire GREYC - UMR6072
2 MSE - Department of Materials Science and Engineering [Blacksburg]
3 NRL - Naval Research Laboratory

The quasi-static magnetic field detection of a layer-bonded Magneto(elasto)Electric (ME) laminate has been investigated by measuring the in-plane electric capacitance via its interdigital electrodes close to the piezoelectric resonant frequency. The ME layered composite is considered as a stress-induced dielectric effect, because there is practically no direct response of the electric capacitance to an external magnetic field [1]. The sensitivity is dominated by the magneto-elastic coupling in the magnetic layer and on the stress which is induced by the permittivity change in the piezoelectric layer. The low frequency magneto-capacitance effect is sensitive to an external magnetic bias which can modulate the electric permittivity by producing a stress. The magnetoelastic coupling is another important parameter for this magnetic field detection mode. For a given magnetic field, the amplitude of the magnetostriction is directly related to this parameter, too [2]. Therefore, an optimal magnetic bias can maximize the induced strain or stress which is coupled into the piezoelectric layer through the change of the electric permittivity in this layer. To evaluate the sensitivity and the noise performance based on the magneto-capacitance effect, we have used the piezoelectric and magnetic constitutive equations to predict the permittivity dependence [16]. Experimentally, this sensor achieved an equivalent magnetic noise spectral density, presently still limited, by the noise of the detection electronics, ~100 pT/√Hz at 1 Hz and offered a DC detection capability. Based on the model and experimental nonlinear factors, an equivalent sensor noise spectral density close to the pT/√Hz can be ultimately predicted taking into account the mechanical loss limitation of the sensor [16].

Mots clés: modulation; magnetic noise; Index Terms—magnetoelectric

Domaines: Electronique

Xin Zhuang, Marc Lam Chok Sing, Christophe Dolabdjian, Yanping Wang, Peter Finkel, et al.. Sensitivity and Noise Evaluation of a Bonded Magneto(elasto)Electric Laminated Sensor Based on In-plane Magneto-capacitance Effect for Quasi-static Magnetic Field Sensing. IEEE Transactions on Magnetics, 2015, pp.10.1109/TMAG.2014.2356852. ⟨10.1109/TMAG.2014.2356852⟩. ⟨hal-01162288⟩