Fig. 7

XPD analysis of the \(\text {Rec}(26\times \sqrt{3})\)-phase. (a) Experimental (left) and simulated (right) XPD patterns for \(\hbox{Sn}\,\hbox{4d}\) photoelectrons with a kinetic energy of \(E_{\text {kin.}} = {211.7}\,\hbox {eV}\). (b) Same as in (a) for \(\hbox{Au}\,\hbox{4f}\) signal with \(E_{\text {kin.}} = {151.6}\,\hbox {eV}\). Simulations for both patterns independently resulted in a \(\text {Rec}(26\times \sqrt{3})\)-reconstruction. The agreement between simulation and experiment for both patterns yielded an R-factor of \(R = 0.04\) each. The obtained structure is displayed in (c). (d) shows the lateral distance from the ideal fcc and hcp stacking sites for the atoms in the top layer of the unit cell. Similar to the herringbone reconstruction of the clean \(\hbox{{Au}(111)}\) surface, alternating hcp and fcc stacking stripes are observed. The width of the hcp stripes, measuring \(\approx {4.5}\,\hbox {nm}\), is larger than the fcc stripes with \(\approx {2.9}\,\hbox {nm}\).