Magnetostrictive Fe-Co-B Alloys for High-frequency Sensor Applications

Fe-rich Fe-Co-B magnetostrictive alloys have been considered as good high-frequency sensor materials. In this paper, Fe-rich Fe-Co-B thin films with the composition of Fe57Co29B14, Fe55Co28B17, Fe53Co27B20, Fe51Co26B23 and Fe49Co25B26 were fabricated. The structure, morphology, magnetic property and resonant behavior of the films were studied. Among the different compositions, Fe55Co28B17 has the highest Q value and relatively high amplitude, which is beneficial for sensor application. Au/Fe55Co28B17/Au magnetostrictive particles (MSPs) were prepared by electrodeposition and microfabrication. The 500 μm×100 μm×6 μm MSP shows a resonant frequency of 3.320 MHz and Q value of 127. Fe-Co-B thin film sensors with good performance can be potentially utilized for high-frequency application and food safety detection.