The reconstructed Au (100)-(5 x 20) surface existed in an electrochemical cell over an extended potential region. This was confirmed directly by in situ measurements of the double-layer capacity, which yielded results which were very similar - possibly identical - to those for Au (111). This was expected, because the (5 x 20) surface presented a top layer of (111) structure. The reconstruction was quite suddenly lifted when the electrode potential was greater than 0.55V. This sudden change from (5 x 20) to (1 x 1) was caused by some adsorption or chemisorption which was strong enough to over-compensate for the energy difference between the 2 structures.

Direct Evidence for Electrochemically Induced Surface Reconstruction - Au (100)-[(5 x 20) → (1 x 1)]. D.M.Kolb, G.Lehmpfuhl, M.S.Zei: Journal of Electroanalytical Chemistry, 1984, 179, 289-95