Abstract
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.
Original language | English |
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Pages (from-to) | 1644-1649 |
Number of pages | 6 |
Journal | Journal of Materials Science |
Volume | 43 |
Issue number | 5 |
DOIs | |
State | Published - Mar 2008 |
Funding
Acknowledgements 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.