E0050

Quasi-periodic Materials – Discovery and Research at NIST. Dan Shechtman, Department of Materials Engineering, Technion, Haifa 32000, Israel.

The discovery at NIST of Quasi-periodic crystals (quasicrystals) in 1982 changed the science of crystallography fundamentally. The change is manifested in the breaking of a paradime and a redifinition of crystal. It is therefore not surprising that, in the first decade after announcement of the discovery, in 1984, the immediate interest was devoted predominantly to fundamental research into the nature of quasicrystals, and to the development of scientific and mathematical tools to accommodate them. A second wave of quasicrystal research has begun in recent years, to consider quasicrystalline materials as a class of engineering materials in their own right, which may compete successfully with conventional materials in industrial and commercial applications.

As a result of the enormous efforts to elucidate the structure of quasicrystals, a firm basis has been established for the science of quasicrystals in a relatively short time, and several families of stable quasicrystals have been identified. Against this background, data have recently been gathered regarding quasicrystal properties, which are potentially of commercial significance.

In this talk we will outline the fundamental changes in our understanding of the structure of matter, and focus on some practical applications of quasicrystalline materials. Some of the current research activities at NIST will be discussed.