Wagner-Traud diagram

Wagner-Traud Diagram, According to the mixed-potential theory, the overall reaction of the electroless deposition, [Eq. (8.2)] can be described electrochemically in terms of three current-potential i-E) curves, as shown schematically in Eigure 8.2. First, there are two current-potential curves for the partial reactions (solid curves) (1) ic =f(E), the current-potential curve for the reduction of ions, recorded from the rest potential E eq M the absence of the reducing agent Red (when the activity of is equal to 1, eq,M E m) and (2) = f(E), the current-potential... 

Figure 8.2. Wagner-Traud diagram for the total (/total) rid component current potential curves (/, / ) for the overall reaction of electroless deposition.

Figure 8.5. Wagner-Traud diagram for electroless Ni(B) deposition E = — 840 mV versus SCE. Electrode area 0.68 cm. (From Ref. 43, with permission from the American Electroplaters and Surface Finishers Society.)...

Wagner-Traud Diagram. According to the mixed-potential theory, the overall reaction of the electroless deposition, [Eq. (8.2)] can be described electrochemically in terms of three current-potential (i-E) curves, as shown schematically in Figure 8.2. 

Figure 8. Wagner-Traud (Evans) diagram for aluminum in aqueous solution, in the absence of dissolved oxygen.

Landolt gave a more detailed description of the Wagner-Traud concept of partial deposition currents. In Figure 8.3 different situations of combinations of partial current densities are described in Evans diagrams. In the gray areas the less noble component is preferentially deposited. 

Pourbaix has shown by means of E-i diagrams (Wagner and Traud type) that the differential principle is applicable only at certain pH values, and the situation when the pH is the same in both the aerated and non-aerated zones is as follows ... 

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