Quasicrystals – A Paradigm Shift in Crystallography?

Abstract

The discovery of quasicrystals had important consequences for our understanding of long-range order in thermodynamic equilibrium, the definition of the term 'crystal' as well as diffraction theory. Quasicrystals have been observed not only at the atomic scale in binary and ternary intermetallic systems, but also at the mesoscale in self-assembled colloids and block-copolymers, and even at the macroscale in packings of hard polyhedra. How important was the discovery of quasicrystals for crystallography? Did it usher in a scientific revolution and a paradigm shift? These questions are discussed following a short overview of the status of quasicrystal research.