Effects of saccharin and thiourea on sulfur inclusion and coercivity of electroplated soft magnetic CoNiFe film

Tetsuya Osaka, Takahiro Sawaguchi, Fumio Mizutani, Tokihiko Yokoshima, Madoka Takai, Yutaka Okinaka

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110 Citations (Scopus)

Abstract

During the course of our recent work performed to develop an electroplated CoNiFe ternary alloy with high saturation magnetic flux density and low coercivity for use in magnetic recording heads, it was observed that two common sulfur-containing additives, saccharin and thiourea, behave differently with respect to the dependence of sulfur inclusion and coercivity of the alloy film on the additive concentration in the plating bath. To understand the cause of this difference, scanning tunneling microscopy (STM) was performed, using Au(111) as the substrate, to examine the structure of the adsorbed layers of the additive molecules. The result revealed that the nature of adsorption is fundamentally different for the two different additives; i.e., the adsorption of saccharin is physical and reversible, whereas thiourea undergoes irreversible chemisorption. This finding is consistent with the known behaviors of the two additives in the electroplating of nickel. In this paper the different effects of saccharin and thiourea in the electrodeposition of CoNiFe alloy are interpreted based on the STM results and relevant information available in the literature on the electrodeposition of nickel.

Original languageEnglish
Pages (from-to)3295-3299
Number of pages5
JournalJournal of the Electrochemical Society
Volume146
Issue number9
DOIs
Publication statusPublished - 1999 Sep

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ASJC Scopus subject areas

  • Electrochemistry
  • Surfaces, Coatings and Films
  • Surfaces and Interfaces

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