Surface lattice transformation due to contact adsorption

The clean surface of metals in vacuum sustains a surface lattice transformation, as described in Sec. 6.1. Similarly, an interfadal lattice transformation takes place also on metal electrodes in aqueous solutions. In general, the interfadal lattice transformation of metal electrodes is affected by both the electrode potential and the ionic contact adsorption. 

For example, the clean surface of single crystals of metallic gold with a (100) plane sustains a surface lattice transformation in vacmun as shown in Eqn. 5-52  

The superfidal (5 x 20) lattice has a greater atomic density and is more stable than the superfidal (1 x 1) lattice on the (100) plane of gold in vacuum. 

The transformation of interfacial lattice that occurs at the anodic critical potential Et is thus regarded as an anion-induced transformation of interfacial lattice. 

Degree of transformation of interfadal lattice (1x1) - (5x20) observed as a function of cathodic potential for a gold electrode with a plane (100) in perchloric add solution A(total) = total interface area A(5x20) s interface area of (5x20) supper lattice. [From Kolb-Schneider, 1988.] 

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