In the early part of the 20th century, x-rays were first used for the investigation of the atomic structure of solids. Until the 1980s experimental evidence suggested that virtually all solid materials were either amorphous or ordered three-dimensional structures with translational and rotational symmetry that were described by classical crystallographic concepts. Since then, a number of structures that stretch the concept of a crystalline material have been discovered. In 1984 a solid phase, known as a quasicrystal, that possessed long-range order but lacked the periodicity of a crystalline material, was observed. At about the same time, novel molecular structures were observed for elemental carbon, and more recently, carbon has been prepared as a two-dimensional material. Some of the recently discovered materials with novel microstructures are reviewed in the present book. Part I of the book describes the structure and properties of quasicrystalline materials while Part II gives an overview of some of the unique phases that have been observed for elemental carbon. These unusual structures are discussed in the context of related materials with traditional crystallographic order.
Includes bibliographical references.