Tailoring the magnetic properties of galfenol film grown on single-crystal diamond

Abstract

The thin film properties are often compromised but can be tuned by optimizing the growth parameters. Galfenol (FeGa), a magnetostrictive material can be used in MEMS technology particularly due to its large magnetostriction coefficient, low saturation and switching fields. Hence the fabrication of high quality FeGa thin film is important. Recently, the growth of FeGa thin film on semiconductor substrate offer a promising platform for micromechanical sensor. Here, we report the successful growth and high magnetic properties of FeGa thin film on single crystal diamond substrate. In order to obtain FeGa thin film with high soft magnetic properties, the variations of the growth parameters including working pressure, Ar flow rate, sputtering power and growth duration are investigated. It is shown that the microstructure, surface morphology, and magnetic properties of the FeGa thin film can be tailored by the growth parameters. Crystallized FeGa thin films with surface roughness less than 1 nm, low coercivity (Hc) of 26.2 Oe, and low saturation magnetization field (Hs) of 450 Oe and high remanence ratio (Mr/Ms) of 0.9 are obtained. The integration of FeGa thin film on diamond promotes the development of device based on magneto-strictive film integrated with semiconductors.