High magnetoelectric effect at low magnetic basing in heterostructure rod of magnetostrictive fibers, piezoelectric tube, and epoxy binder

Abstract

A three-phase heterostructure rod of 35 mm length and 8 mm diameter is developed by embedding 18 pieces of length-magnetized Tb0.3Dy0.7Fe1.92 magnetostrictive continuous fibers in a wall-thickness-polarized Pb(Zr, Ti)O3 piezoelectric long-thin tube using an epoxy binder in order to study its magnetoelectric (ME) effect for passive sensing of axial magnetic fields. The heterostructure rod exhibits a high non-resonance ME voltage coefficient (αV) of 38 mV/Oe for frequencies up to 10 kHz and an ultrahigh resonance αV of 680 mV/Oe at 32 kHz, both under a reasonably low magnetic bias field (HBias) of 120 Oe. The simultaneously high axial ME responses at the reasonably low HBias, as confirmed theoretically and experimentally, can be ascribed to the realization of the relatively true magnetostrictive 33-mode and piezoelectric 31-mode of operation in the magnetostrictive continuous fibers and piezoelectric long-thin tube, respectively, as well as the reduction in the effect of demagnetization fields in the high aspect-ratio magnetostrictive continuous fibers.