Metglas/Pb(Mg1/3Nb2/3)O3-PbTiO3 magnetoelectric gradiometric sensor with high detection sensitivity

We developed a novel biaxial magnetoelectric (ME) gradiometer sensor system using Metglas/ Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ laminates for investigation of ac magnetic dipole detection. We demonstrate a detection sensitivity of 20 pT/√Hz in an open environment (unshielded) at quasi-static frequencies with a noise rejection efficiency of 23.5 dB, relative to a uniform external noise. In addition, a signal processing method was used to compute the magnetic field amplitude at a driven frequency of 7 Hz, and the results were also verified by theory. Practical testing and mathematical predictions show that there are only 7.2% and 4.2% gradiometric measurement errors in the x- and y-axis gradiometer components, enabling high-precision target detection.