Quasicrystalline d-AlCuCo identified as random tiling by ion channeling combined with particle-induced X-ray emission

In a model quasicrystal for decagonal AlCuCo the phason disorder was gradually increased and the channeling particle-induced x-ray emission (PIXE) yields were computed for 3 MeV He ions by Monte Carlo simulations. For large phason disorder good agreement with experimental data was obtained. Thus we conclude that the sample of d-AlCuCo used in the measurements is a random tiling. One remaining discrepancy, namely, that the PIXE yields of the simulations are approximately the same for Cu and Co, is eliminated by optimization of the Cu and Co positions.