Microstructure and magnetic properties of electrodeposited cobalt films
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Cobalt films were electrodeposited onto both iron and copper substrates from an aqueous solution containing a mixture of cobalt sulfate, boric acid, sodium citrate, and vanadyl sulfate. The structural, intermetallic diffusion and magnetic properties of the electrodeposited films were studied. Cobalt electrodeposition was carried out in a passively divided cell aided by addition of vanadyl sulfate to keep the counter electrode clean. The divided electrolytic cell with very negative current densities cause the electrodeposited Co to adopt a face-centered cubic (fcc) structure, which is more magnetically reversible than the hexagonally close-packed (hcp) structured Co. The coercive field is also significantly less in the fcc-electrodeposited cobalt than in the hcp. SEM images show dense, uniform Co films without any cracks or porosity. Beside the deposition current, thickness of the film was also found to affect the crystal orientation particularly on iron substrates. Diffusion of cobalt film into the iron substrate was studied under reduced environment and a fast process was observed.
KeywordsCopper Substrate Iron Substrate FeCo Alloy Cobalt Film Vanadyl Sulfate
The authors would like to thank Rad Radhakrishnan for helpful discussions and Lee Heatherly for Auger analysis. Also, thanks go to ORISE and HTML Share facilities. This work was sponsored by the Department of Energy, Office of Basic Energy Sciences—Division of Materials Sciences and Engineering, Office of Electricity Delivery and Energy Reliability (OE). This research was performed at the Oak Ridge National Laboratory, managed by UT-Battelle, LLC for the USDOE under contract DE-AC05-00OR22725U.S.
- 9.Grochowski E, Scranton RA, Croll I (1994) In: Romankiw LT, Herman DA Jr (eds) Magnetic materials, processes, and devices III, vol PV 94-6. The Electrochemical Society Proceedings Series, Pennington, NJ, p 3Google Scholar
- 11.Croll IM (1980) Advances in X-ray analysis, vol 4. Plenum Press, New York, p 151Google Scholar
- 12.Croll IM, May BA (1987) In: Romanikiw LT, Turner DR (eds) Electrodeposition technology, theory and practice, vol PV 87-17. The Electrochemical Society Proceeding Series, Pennington, NJ, p 295Google Scholar
- 15.Nishizawa T, Ishida K (1986) Met Prog 129(2):57Google Scholar
- 17.Bozorth RM (1991) Ferromagnetism. IEEE, New York Google Scholar