High-temperature multiferroic magnetoelectric sensors

Abstract

Magnetoelectric (ME) sensors are an important tool to detect weak magnetic fields in the industry; however, to date, there are no high-quality ME sensors available for high-temperature environments such as engines, deep underground, and outer space. Here, a 0.364BiScO3–0.636PbTiO3 piezoelectric ceramic and Terfenol-D alloy with a Curie temperature of 450 and 380 °C, respectively, were bonded together by an inorganic glue to achieve a high-temperature ME sensor. The ceramic shows a piezoelectric d33 coefficient of 780 pC/N at 420 °C, and the inorganic glue has a high maximum stress of 9.12 MPa even at 300 °C. As a result, the sensor exhibits the maximum ME coefficient αE of 2.008, ∼1.455, and ∼0.906 V cm−1 Oe−1 at 20, 200, and 350 °C, respectively. Most importantly, the magnetic field detecting precision is as small as 42 nT at 20–350 °C. The ME sensor provides an effective solution for the detection of weak magnetic fields in harsh environments.