Magnetoelectric laminated composites of lead-free BSZT and magnetostrictive materials

A magnetostrictive-piezoelectric laminated composite has been developed by sandwiching a lead-free Sr modified BZT piezoelectric ceramic plate between two magnetostrictive materials plates polarized in the thickness direction. Two different magnetostrictive materials, Terfenol-D continuous fiber composite (TD-FC) and cobalt ferrite (CFO), were used to fabricate the ME composite laminates. The quasistatic magnetostrictive properties of the magnetostrictive samples were measured and the quasistatic (differential) strain coefficient (\( d_{33}^{QS } \)) can be found. Lead-free magnetoelectric (ME) laminated composite has a good ME voltage sensitivity (ME _v ) under a low magnetic bias field (H _Bias ). The BSZT/TDFC laminate has ME _v  = 0.888 V/Oe at the resonance frequency of 119 kHz under a H _Bias of 0.6 kOe. The BSZT/CFO laminate has ME _v  = 0.155 V/Oe at the resonance frequency of 204 kHz under a H _Bias of 0.4 kOe. A prototype magnetic field sensor was fabricated and characterized under different frequency and different field strength. This work shows the potential of BSZT lead-free ceramics in magnetic field sensing application.