Residence time and structure of alloys

By comparing the residence times an image of the selectivity of the surface for the electrolyte components can be developed. The deposition of an alloy of two similarly sized components A and B has been chosen as an example. By a suitable selection of the experimental parameters (concentration of metal ions, complexing agents, potential, etc.), the deposition rates of A and B can be made equal and equivalent to the equal partial current densities = ig. Therefore one can distinguish between three cases. 

If a metal atom A or B is deposited into a kink site position, regardless of the character of the kink site position, in each case it will stay for a similar time in this position as all other atoms deposited. All kink site positions are of similar stability. If during this time a second atom arrives (B or A) the position of the firstly deposited atom in the crystal lattice is fixed. The deposition rates are similar an attachment of atoms A or B is of similar probability. The situation leads to a homogeneous mixture between A and B. This is called a solid solution. 

If the kink site position AB is much less stable then the position AA or BB and has equal rates of deposition, the formation of pure crystallites of atoms A and B is preferred. This is the typical situation when a eutectic mixture is formed. 

Under these conditions the kink site position AB is much more stable than for A A or BB. If kink site positions AA or BB are formed, one can expect that either atom A or B will 

Under these conditions a stoichiometric alloy or an intermetallic compound is formed. 

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