291228 Effect of Sulfur Incorporation on CoFeNi Alloys

Monday, October 29, 2012
Hall B (Convention Center )
Paul Abraham, Chemical and Biomolecular Engineering, University of Houston, Houston, TX

Effect of Sulfur Incorporation on CoFeNi Alloys

 

P. Abraham1*, N. Dole1, D.W. Lee2, A. Papou2, W. French2, and S. R. Brankovic1

 

1Cullen College of Engineering, University of Houston, TX 77204-4005

2Texas Instruments Inc., Santa Clara, CA 95052-8090

The increasing demand for areal density in magnetic recording has led to the design of magnetic materials with high saturation magnetization and low coercivity. Alongside these properties, low growth stress and high resistivity are also desired.

Electrodeposition has provided a mechanism to control these properties by usage of an additive in the chemical bath used for depositioni,ii,iii. For the experiments presented, saccharin was used as the additive. Data from experiments carried out to relate the concentration of saccharin used as an additive to growth stressii, resistivity, magnetic propertiesiii, and crystal structure of electrodeposited CoFeNi thin films are presented.

The saccharin concentrations were varied between 0 gL-1 and 2 gL-1. The galvanostatic deposition was carried out in a quartz cell on a Cu substrate using an experimentally determined current density. The stress measurements were performed in situ(during the deposition) using the cantilever-curvature method. The resistivity of the alloy was determined using four point probe measurements. Magnetic properties were determined using the vibrating sample magnetometer. The crystal structure of the alloy was analyzed using an X-ray diffractometer.

As seen in Figure 1, no appreciable change in crystal structure was observed with varying saccharin concentrations. However, Figure 2 shows that variances in coercivity did result due to variance of saccharin concentration in the bath and show a predictable trend with saccharin concentration. Similar trends in resistivity and growth stress are presented in the poster.

References:

iT. Osaka, T. Sawaguchi, F. Mizutani, T. Yokoshima, M. Takai, and Y. Okinaka, Journal of the Electrochemical Society, 146, 3295 (1999)

iiS. R. Brankovic, B. Kagahwala, J. George, G. Majkic, G. Stafford, P. Ruchhoeft, Electrochemical Acta, 83, 387 (2012)

iiiJ. Geroge, S.-E. Bae, D. Litvinov, J. Rancheler, and S.R. Brankovic, Journal of the Electrochemical Society, 155, D589 (2008)


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