Scanning tunneling microscopy of a polygrain Al-Pd-Re quasicrystal: Study of the relative surface stability

Scanning tunneling microscopy and x-ray photoemission spectroscopy on a polygrain icosahedral (i-) Al-Pd-Re quasicrystal (QC) show the formation of the twofold surfaces with symmetry and composition expected from the bulk. The predominant occurrence of the twofold surface on the polygrain i-QC having random grain orientation, as well as preferential formation of terrace edges, kinks and voids along the twofold axes, consistently indicates that the twofold surface, which has the highest atomic density, is the most stable among all the crystallographic planes.