M. Erbudak et al., REAL-SPACE IMAGING OF PENTAGONAL SYMMETRY ELEMENTS BY 2KEV ELECTRONS IN THE ICOSAHEDRAL QUASI-CRYSTAL AL70MN9PD21, Physical review letters, 72(19), 1994, pp. 3037-3039
Pentagonal symmetry elements in an icosahedral quasicrystal are unambi
guously observed for the first time in real space using the technique
of secondary-electron imaging.