DIRECT CONFIRMATION OF THE QUASI-CRYSTALLINE STRUCTURE OF A T-PHASE QUASI-CRYSTAL BY ION CHANNELING COMBINED WITH RUTHERFORD BACKSCATTERING

The channeling properties of a T-phase Al62CU20CO15Si3 quasicrystal are investigated in a Rutherford-backscattering study using 2-MeV He ions. Besides axial channeling along the decagonal axis, planar channeling is observed in planes having the decagonal axis in common and showing the decagonal symmetry of the quasicrystal. Besides a system of main planes, various planes exhibiting only weak channeling properties are observed; they correspond to linear arrangements of vertices in a two-dimensional Penrose grid, demonstrating the close relationship between T-phase quasicrystals and Penrose pattern.