Quasicrystals: Structure and stability

Since their discovery in 1984, several thousand papers have been published dealing with various aspects of quasicrystals. Despite this flurry of activity, questions concerning the development, structure, and physical properties of this new phase remain only partially answered. This article reviews investigations of the formation and stability of quasicrystals. A pedagogical approach is taken. A brief survey of atomic and structural models, defects, and metallurgical properties of selected systems is provided as necessary background. While most attention is focused on the icosahedral quasicrystalline phase, one section is devoted to another common quasicrystal, the decagonal phase. Aluminium based quasicrystals are most common and are reviewed here; the first review of titanium based quasicrystals is also provided.