Enhanced Sensitivity and Reduced Noise Floor in Magnetoelectric Laminate Sensors by an Improved Lamination Process

Abstract

The effect of lamination process on the performance of Metglas/Pb(Zr,Ti)O3‐based composite magnetoelectric (ME) sensors has been studied. Improved sensor processing can lead to higher coupling between the magnetostrictive and piezoelectric phases. A higher coupling factor results in higher magnetic field sensitivity and lower equivalent magnetic noise floors. Spin‐coat/vacuum‐bag application and cure of interfacial epoxy, in addition to the use of Metglas foils with enhanced magnetostriction (λ = 42 ppm), has led to an increase in the ME coefficient from 6 to 21.6 V/cm·Oe, and a decrease in the 1 Hz equivalent magnetic noise from 2 × 10−10 to 4 × 10−11 T/√Hz.

Status and Perspectives of Multiferroic Magnetoelectric Composite Materials and Applications

“…Efforts have focused on: (a) different categories of sensor construction [24,[74][75][76], geometry and other features [77][78][79][80]; (b) packaging of the sensor units; (c) improvements in fabrication techniques [81]; (d) signal processing conditions [82,83]; and (e) gradiometric configurations to reduce environmental noise sources [84]. The multi-push-pull configurations, multilayer configuration, and bimorphs, all of which exhibit an improved ME voltage coefficient, have demonstrated considerable potential for sensing low-frequency magnetic field variations.…”

Enhanced magnetoelectric effect in self-stressed multi-push-pull mode Metglas/Pb(Zr,Ti)O3/Metglas laminates

“…2(b), without self-stress in the laminate, the maximum value of a ME was 25.3 V/cm Á Oe, which agrees well with data previously reported. 15 However, for H bias ¼ 20 Oe, the maximum value of a ME was 31.4 V/cm Á Oe, which was a factor of 1.24Â higher than that for H bias ¼ 0. This value of a ME in the self-stressed state is higher than any data ever reported for ME laminates having a core PZT layer.…”

“…Spin-coat and vacuum-bag techniques were used to keep good repeatability of the capacitances of the interdigitated electrode/PZT core composites. 15 The core composites were poled under 20 kV/cm electric field. Three Metglas foils (Vitrovac 7600 F, Hanau, German) of dimensions 80 mm  10 mm were then laminated to both the top and bottom surfaces of the core piezoelectric composites.…”

Enhancement in magnetic field sensitivity and reduction in equivalent magnetic noise by magnetoelectric laminate stacks

“…9 The highest value of a ME reported for Metglas/Pb(Zr,Ti)O 3 (PZT) two phase laminates is 22 V/cm Á Oe. 5,10 Much higher values of a ME ¼ 52 V/cm Á Oe have been achieved for Metglas/Pb (Mg 1/3 ,Nb 2/3 )O 3 -PbTiO 3 (PMN-PT) laminates. 7 The reduction of the equivalent magnetic noise for ME magnetic sensors is difficult.…”