Nucleation of Tin and Tin–Silver Alloy on Copper and Nickel in Acid Plating Baths

Abstract

The rate of nucleation and number density of nuclei of tin and tin-silver deposits on copper and nickel substrates in acid sulfate and acid methanesulfonate baths were measured by application of a nucleation model to chronoamperometric data. Based on the dependence of nucleation rate on overpotential, the critical Gibbs free energy of nucleation and the critical nucleation size were calculated. A mechanism of alloy nucleation in the presence of thiourea is proposed.

Electrochemical Behavior of Nanostructured Fe-Pd Alloy During Electrodeposition on Different Substrates

“…It should be pointed out that the well-known theories in the case of electrochemical nucleation and growth have been developed for single metal and/or single phase electrodeposition, such as Scharifker et al [45,46] and Heerman-Tarallo [47,48] models. However, a literature survey shows that in many cases these models have been successfully utilized not only for binary alloy [1,6,16,[49][50][51][52][53][54][55][56][57][58][59][60][61] but also for ternary alloy electrodeposition [62][63][64]. The well-known model of Scharifker and Hills [45] has been used for many multicomponent electrodeposition systems such as Fe-Ni [1,59], Fe-Co [50,60], Fe-Zn [61], Pd-Rh-Ru [62] and Fe-Pd [6].…”

“…In this model, it is assumed that nucleation is initiated at susceptible energetic sites such as dislocations, steps, kinks, grain boundaries, nubs, and etc [42,49,65,66]. According to Avrami's theory, the number of active nucleation sites (N) as a function of time (t) is estimated as: (2) where A and N 0 are the constant rate of nucleation and the number of final nuclei [65] (or number of active sites on the surface [49,66]), respectively; which depend on the electrolyte and cathodic potential [45,46]. When At is large enough ( ), nucleation occurs instantaneously and all nuclei are formed at the same time.…”

Complexing agent study for environmentally friendly silver electrodeposition(ii): electrochemical behavior of silver complex

“…In the progressive nucleation process, eqn ( 5)-( 8) are always used for the study of diffusion coefficient, the nuclear number density, and nucleation rate constant. 22,29,45,[49][50][51] t m ¼ 4:6733…”