ABSTRACT
Introduction e ever expanding demand of the world market leads to magnetic recording data storage devices advancing toward much smaller exterior dimension and higher capacity [1, 2]. In order to achieve very high capacity and fast recording data storage in a miniature device, an ultrasoft and high magnetic moment material is required for producing high-saturation ux density (Bs), so that the necessary ux density can be preserved on reducing device dimensions, while simultaneously achieving a low coercivity (Hc) to match the hard magnetic media with high Hc, track density, and linear density [3]. Soft magnetic lms with high moment are also widely used in modern electromagnetic devices, such as high-frequency eld-amplifying components, versatile communication tools, and magnetic shielding materials in tuners [4]. Although numerous soft or high-Bs magnetic lms have been achieved nowadays via sputtering, evaporation, and casting, most of them cannot be applied to device fabrication due to the following reasons: low-deposition rate (usually < 8 Å/S) and high-internal stress lms from sputtering [5], overly thick lms (commonly > 1 mm) from casting, and coarse-grained lms from evaporation [6]. In addition, most of the reported materials have limited Bs of ≤ 2.1T (e.g., NiFe, FeCoNi lms) [3]. Despite CoFe alloy possessing the highest Bs of about 2.45T theoretically, the CoFe nano/microlms prepared always encounter two vital issues for application: poor magnetic properties [such as poor anisotropy, high value of Hc (always > 4 Oerted (Oe))] and poor mechanical properties (such as rough surface, and cracking lm) [7]. Electrodeposition is a fast and simple method to achieve various thicknesses of soft Fe-based materials with lower stress [8, 9]. However, preventing Fe2+ from oxidization into Fe3+ (which decreases Bs), and minimizing the Hc and roughness of the metal lms are challenges in electrodeposition [3, 7]. So far, only the softest magnetic CoFe lm, which possesses an easy axis Hc (Hce) and hard axis Hc (Hch) of 15 and 4.8 Oe, respectively, has been reported [7].
