Magnetostriction in electroplated CoFe alloys

The phenomenon of magnetostriction can wirelessly couple external magnetic fields to generate structural motion. This is an attractive solution for remote delivery of power to microactuators in constrained environments. This study discusses the magnetostriction of electrosynthesized CoFe thin film microactuators. Electrodeposition is commonly employed for the fabrication of metallic thin films, however the magnetostriction of such films has been rarely investigated. In particular, the magnetostrictive behavior of electroplated CoFe films is poorly understood, despite the high magnetostriction capabilities of CoFe alloys. In this work, uniformly thick and smooth Co0.65Fe0.35 thin films were electrochemically grown on commercially available micron-scale cantilevers. The CoFe thin films were characterized for their morphology, composition, crystal structure, and magnetic properties. The AC magnetostrictive response of the cantilevers was measured interferometrically and the actuator exhibited a maximum expected displacement of 86nm.