The anomalous codeposition of tungsten in the presence of nickel

摘要: Abstract Deposition of tungsten-rich alloys from plating baths that do not contain ammonia is reported. Alloys with nominal composition NiW and even NiW2 have been formed for the first time by electroplating. It was shown in this paper, our previous work [Electrochem. Solid-State Lett. 3 (2000) 543; Proc. Advanced Metalization Conf. (AMC 2000) p. 337; Langmuir 17 (2001) 8270; J. Electrochem. Soc. 149 (2002) C100; Appl. Surf. Sci. 200 1], tungsten nickel having any between a few a/o 67 can be electroplated, suitable choice experimental conditions. The most important factors among these are concentrations citrate, which acts as complexing agent, ratio tungstate ions pH solution. New indirect evidence existence mixed metal complex type [(Ni)(WO4)(Cit)(H)]2− obtained by: (a) dependence alloy (b) linear partial current density deposition on calculated concentration complex, over wide range solution compositions. Removing bath allows alloys, but achieved at cost substantial reduction Faradaic efficiency.