A pencil-like magnetoelectric sensor exhibiting ultrahigh coupling properties

Abstract

A one-dimensional pencil-like magnetoelectric (ME) sensor prototype is proposed which consists of a magnetostrictive cylinder, a truncated conical spacer, and a piezoelectric disk assembled in a rigid frame. By adopting the displacement-transfer mode in this sensor, not only the strain loss at the ME interface is avoided but also the volume fractions of both phases can be adjusted in a broader range. Using a nonlinear magnetostrictive model and linear piezoelectric model, the ME coupling performance of this sensor is systematically analyzed using lead titanate zirconate (PZT) disks and Terfenol-D cylinder as the components. Results show that such a sensor can practically exhibit giant quasi-static ME field coefficients (αE) and charge density coefficients (αD) as high as 455 V/cm Oe and 480×10−6 C/m2 Oe, which is about 10 times and 100 times higher than the best reported values, respectively. Furthermore, the ME coupling properties will decrease considerably when the stiffness of the frame is reduced. The proposed pencil-like ME sensor in this work could be very helpful in the design of ultrasensitive magnetic-field sensors and other ME coupling devices.