The effect of tartrate on the morphological and structural characteristics of lead-tin electrodeposit from an alkaline bath

The electrodeposition of Pb-Sn alloys from a tartrate-alkaline plating bath can lead to a deposition of pure lead or a normal codeposition of lead-tin depending on the deposition potential. The percentage of tin in the Pb-Sn deposit obtained at similar to-1.15 V increases from 4.08 wt.% to 20.7 wt.% as the charge density rises from 2.5 C cm(-2) to 5.0 C cm(-2) and then decreases from 12.07 wt.% to 7.52 wt.% as the charge density rises from 7.5 C cm(-2) to 10.0 C cm(-2). SEM images show that the Pb and Pb-Sn deposits obtained from a tartrate-alkaline bath did not, in general, show dendritic growth. X-ray analysis of the deposits obtained at -0.83 V with 5.0 C cm(-2) or 10.0 C cm(-2) indicated the presence of Pb and Pb2PtO4 and the absence of Sn. However, those obtained at -1.15 V and the same charge densities (q(d)) showed the presence of Pb, Pb2SnO4, PbSnO3 and PtSn4. The Pb2PtO4 and PtSn4 compounds were formed because the electrodeposition process occurred onto Pt substrate. (c) 2007 Elsevier B.V.All rights reserved.