High sensitivity magnetic sensor consisting of ferromagnetic alloy, piezoelectric ceramic and high-permeability FeCuNbSiB

Abstract

A high sensitivity magnetoelectric (ME) composite sensor employing a type of ferromagnetic constant-elasticity alloy (FeNi-FACE), piezoelectric Pb(Zr,Ti)O 3 (PZT-8H) and high-permeability FeCuNbSiB (Fe 73.5Cu 1Nb 3Si 13.5B 9) is developed. The FeCuNbSiB ribbon with the high permeability serves as the dynamic driver to increase the effective piezomagnetic coefficient d 33 of the FeNi-FACE. At the same time, the FeCuNbSiB/FeNi-FACE/PZT-8H/FeNi-FACE/FeCuNbSiB (FeFPFFe) composite sensor exhibits a higher effective mechanical quality factor ( Q m), which is ∼7.7 times higher than that of Terfenol-D/PZT-8H/Terfenol-D (MPM) sensor. As the ME voltage at resonance is directly proportional to the product of piezomagnetic coefficient and Q m, a stronger ME effect can be achieved. The experimental results show that the resonance ME voltage coefficient (MEVC) of the FeFPFFe sensor at H dc = 119 Oe achieves 4.367 V/Oe, which is ∼1.41 times higher than that of FeNi-FACE/PZT-8H/FeNi-FACE (FPF) sensor. Furthermore, ∂ V ME / ∂ H dc for the FeFPFFe sensor achieves ∼22.5 m V/Oe at H dc = 31 Oe under resonant drive conditions of H ac = 0.1 Oe, which is ∼20 times higher than that of the previous reported Terfenol-D/Pb(Zr,Ti)O 3/Terfenol-D composite transducer. Thus the FeFPFFe sensor has highly sensitive ac or dc magnetic field sensing.