We demonstrate that high-Bs laminated CoNiFe alloys with improved soft magnetic properties can be deposited by plating current density modulation in a single plating bath. The laminated material consists of high-Bs CoNiFe layers with bcc crystal phase and thinner intermediate layers of softer CoNiFe with mixed fcc + bcc crystal phase. The electrodeposition method presented here offers advantages for laminated magnetic alloy fabrication over the use of multiple plating cells. These include simple plating hardware requirements and elimination of the risk for corrosion due to multiple substrate transfer steps.
High iron (> 80%) nickel-iron (NiFe) films were electroplated via direct current from a sulfate/chloride bath. When used as the head core material in perpendicular magnetic recording (PMR) write heads, these magnetically soft, high stress, and low magnetostriction (in comparison to NiCoFe and CoFe films) NiFe electroplates were found to be an acceptable potential candidate for the first generation of PMR recording heads.
Additives play an important role in thin magnetic alloy electrodeposition since they impact the film grain boundary, the nucleation and growth mechanism. Consequently, they significantly determine the film properties.
In this study, we have evaluated a α-hydroxy sulfone compound as plating additive (Hydroxymethyl-P-Tolylsulfone or HPT was used as a case study) in CoNiFe and CoFe electrodeposition processes. From the chemical nature of HPT, the major drawback of this compound is its poor stability in aqueous medium in the presence of air. Analytical (HPLC) and electrochemical methods have been utilized to identify the compound decay mechanism and behavior. The HPLC spectrum of HPT and its decay by-products are compared to those of pure known compounds in Fig 1. With HPT added into CoNiFe and CoFe electrolytes, a strong grain refining effect was noticed in the deposits and the related film properties (magnetic, morphology and corrosion properties, etc.) have been characterized accordingly.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.