Improving the characteristics in magnetostrictive-piezoelectric sensors when the viscous interface is removed

This paper presents the results obtained with a prototype of a magnetostrictive-piezoelectric magnetic sensor where the ferromagnetic material has been grown by sputtering over the piezoelectric support where a copper layer has been previously deposited and electrolitically polished. In this way, the coupling between the piezoelectric and the ferromagnetic materials is stronger than that obtained by using a viscous fluid between both materials, as it is used to be. The most significant advances are the good sensitivity of 0.5 mV/mu T for a 1.5-mu m-thick ferromagnetic layer and the important reduction of the magnetic hysteresis due to the piezoelectric vibration. (C) 2000 Elsevier Science S.A. All rights reserved.