Investigation on microstructures and phases of Fe-Ga alloy films deposited by magnetron sputtering

Abstract

Galfenol (Fe-Ga alloy), as a new magnetostrictive materials, has potentially wide applications in magnetostrictive devices. In this work, Fe-Ga alloy thin films were prepared by slice-style target magnetron sputtering and investigations on microstructures and phases of Fe-Ga alloy films were made to explore the relationship of properties and microstructures. The results show that the component of alloy thin film is related to physical properties of the material itself as well as the area ratio of the patch and target. The phase formed in the films in is disorderly A 2 phase with face-centred cubic structure. The films prepared by magnetron sputtering exist in the form of polycrystalline with <110> crystallographic texture perpendicular to the film plane. The structure shape of as-deposited specimens present a maze domain with different contrast and resolution and the magnetic domain decreased with the increase of the Ga content. With the increase of the Ga content, the magnetic domains become more and more irregular. Fe-Ga thin film morphology is related to the growth mode of the film. The microstructures of Fe-Ga alloy films can be controlled by magnetron sputtering technology.

Composition Regulation and Microstructure Characterization of Fe100-xGax Films in the Manufacturing Industry

“…Its surfaces were cleaned by ultrasonic before sputtering. The thickness of films can be calculated by the weighing method [23]. The average value is taken as the thickness of films to reduce errors in the experiment.…”

“…A theoretical equation can be used to calculate film compositions. The theoretical formula of film composition can be deduced as follows [23].…”

“…However, gallium content only stems from the Fe 100-x Ga x target. Thus, the relative contents of 3 Journal of Sensors iron and gallium of Fe 100-x Ga x films can be expressed as formula (12) and formula (13).…”

“…where m Fe % and m Ga %, respectively, mean iron and gallium content in the sputtered films from Fe 100-x Ga x targets uncovered with iron, and M Fe % and M Ga % separately represent the actual content of iron and gallium in the sputtered films. Formulas ( 14) and ( 15) are given by means of substituting expression (11) into formulas (12) and (13).…”

“…However, the traditional mosaic target must be drilled in order to embed the second material on the surface of the matrix target, which will produce gap on the target, affect the electromagnetic field uniformity, and affect the sputtering process. Against this background, Yan et al report a composite or improved mosaic targets to tune Fe 100-x Ga x film compositions [13].…”