Evaluation of high‐sensitivity FeGa/PZT stacked‐layer magnetic sensor

Abstract

AbstractAn FeGa/PZT stacked‐layer magnetic sensor was studied. The prototype sensor was 15 mm long and 6 mm wide with two 880‐μm‐thick FeGa layers and a 590‐μm‐thick PZT layer. The theoretical sensitivity using a simple model was calculated to be 69.6 mV/Oe. The resonant modes were analyzed using an FEM simulator, resulting in a fundamental resonant frequency of 5.38 kHz. A magnetic field was applied to the longitudinal direction of the fabricated sensor to cause longitudinal stress magnetostrictively, which produced a piezoelectric output voltage in the PZT layer. The dependence of the magnetic sensitivity on the DC bias magnetic field was evaluated, together with the frequency characteristics and the temperature dependence. The measured sensitivity roughly agreed with the calculated one. A prototype with a single magnetostrictive layer was also fabricated and evaluated to investigate the possibility of operation as a resonant sensor. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(5): 1–7, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11392