A quasi-unit cell model for Al-Ni-Co Ideal Quasicrystal based on clusters with broken 10-fold symmetry

TL;DR

This paper introduces a quasi-unit cell model for the Al-Ni-Co decagonal quasicrystal, emphasizing overlapping clusters with broken symmetry, which better fits electron microscopy data than previous models.

Contribution

It proposes a new atomic model based on broken 10-fold symmetry clusters that improves the fit to experimental data over prior models.

Findings

The model supports the quasi-unit cell description of the quasicrystal.

Overlapping decagonal clusters with broken symmetry better match microscopy data.

The proposed model significantly improves the fit compared to previous proposals.

Abstract

We present new evidence supporting the quasi-unit cell description of the $Al_{72}Ni_{20}Co_{8}$ decagonal quasicrystal which shows that the solid is composed of repeating, overlapping decagonal cluster columns with broken 10-fold symmetry. We propose an atomic model which gives a significantly improved fit to electron microscopy experiments compared to a previous proposal by us and to alternative proposals with 10-fold symmetric clusters.