Abstract

Jon Mallett
NIST, Gaithersburg , MD

October 31 , 2007
3:30- 4:30pm
Wilsdorf Rm. 101

"Electrodeposition and Properties of Pt alloy Films"

ABSTRACT:

The electrodeposition of iron-group platinum alloys will be described. An undepotential alloy co-deposition mechanism is proposed, by which the reactive component is co-deposited at more positive potentials than occur during elemental deposition. This positive shift in the deposition potential for the alloy can be an advantage because it can help in reducing the parasitic generation of hydrogen and the associated formation of oxides and hydroxides. The potential dependence of alloy composition will be shown to be in good agreement with the thermodynamics of alloy formation and unusually insensitive to solution concentrations. This strong and predictable dependence on deposition potential and weak dependence on concentration makes the deposition process especially uniform and controllable. The magnetic properties of some of the Fe-group alloys will be briefly discussed. A similar deposition mechanism will be used to describe the electrodeposition of CuPt alloys. In this case, more favorable deposition conditions allow better characterization of the initial stages of the deposition process using charge measurements combined with a quartz crystal microbalance. Preliminary results of electroless CuPt deposition will also be presented.

[return to seminar schedule]