Strain-Modulated Multiferroic Magnetic Field Sensor for Operation up to 500 °C

• Published in: IEEE sensors letters Vol. 8; no. 10; pp. 1 - 4
• Main Authors: Acosta, Sydney, Tan, Jonathan, Aslam, Muhammed Zubair, Li, Zekun, Mion, Thomas, Staruch, Margo, D'Agati, Michael, Finkel, Peter, Bussmann, Konrad, Allen, Mark, Olsson, Roy H.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01-10-2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bias; Concentrators; Density; high-temperature magnetometer; Magnetic fields; Magnetic flux; Magnetic sensors; Magnetometers; Magnetostriction; multiferroic sensor; Noise sensitivity; Sensors; Spectral sensitivity; strain modulation; Temperature measurement; Temperature sensors
• ISSN: 2475-1472; 2475-1472
• DOI: 10.1109/LSENS.2024.3433520

Magnetic field sensors that can operate at temperatures above 300 °C are necessary for sensing in harsh environments. A strain-modulated sensor composed of AlN and FeCo paired with an AlNiCo magnetic bias circuit and FeCoV flux concentrators capable of operation from 25 to 500 °C is presented. The total package size, including the bias circuit and flux concentrators, is 0.4 cm 3 , and at 500 °C, the noise spectral density of this sensor is 26 nT/√Hz for a 100 Hz signal. At 500 °C, the sensor has a Q factor of 1366 and a theoretical bandwidth of 2.5 kHz. The noise spectral density and sensitivity are reported for various temperatures as the temperature is heated from 25 to 500 °C and subsequently cooled from 500 to 25 °C.