Quasicrystals
نویسنده
چکیده
The discretely diffracting aperiodic crystals termed quasicrystals, discovered at NBS in the early 1980s, have led to much interdisciplinary activity involving mainly materials science, physics, mathematics, and crystallography. It led to a new understanding of how atoms can arrange themselves, the role of periodicity in nature, and has created a new branch of crystallography.
منابع مشابه
Rhombellanic Crystals and Quasicrystals
Design of some crystal and quasicrystal networks, based on rhombellane tiling,is presented. [1,1,1]Propellane,is a synthesized organic molecule; its hydrogenated form, the bicyclo[1.1.1]pentane,may be represented by the complete bipartite graph K2,3 which is the smallest rhombellane. Topology of translational and radial structures involving rhombellanes is described in terms of vertex symbol, c...
متن کاملQuasicrystals pdf
In contrast to periodic crystals, quasicrystals exhibit a long range order in spite. The diffraction pattern of quasicrystals shows a dense set of Bragg peaks with.It is argued that the prevailing definition of quasicrystals, requiring them to. Restrict the definition of quasicrystals by requiring that they possess an axis.Abstract. It is argued that the definition of quasicrystals should not i...
متن کاملBand Structure and Dispersion Properties of Photonic Quasicrystals
In this paper, for developing analytical and semi-analytical methods to evaluate band structure in photonic quasicrystals the perturbation theory is examined. It is shown that more isotropic and complete photonic band gap can be observed under low dielectric contrast for photonic quasicrystals in comparison with ordinary crystals and because of this feature of photonic quasicrystals, perturbati...
متن کاملObservation of topological phase transitions in photonic quasicrystals.
Topological insulators and topological superconductors are distinguished by their bulk phase transitions and gapless states at a sharp boundary with the vacuum. Quasicrystals have recently been found to be topologically nontrivial. In quasicrystals, the bulk phase transitions occur in the same manner as standard topological materials, but their boundary phenomena are more subtle. In this Letter...
متن کاملDefects in Static Elasticity of Quasicrystals
A review on mathematical elasticity of quasicrystals is given. In this review, the focus is on various defects of quasicrystals. Dislocation and crack are two classes of typical topological defects, while their existence has great influence on the mechanical behavior of quasicrystals. The analytic and numerical solutions of dislocations and crack in quasicrystals are the core of the static and ...
متن کاملRegular Polytopes, Root Lattices, and Quasicrystals*
The icosahedral quasicrystals of five-fold symmetry in two, three, and four dimensions are related to the corresponding regular polytopes exhibiting five-fold symmetry, namely the regular pentagon (H2 reflection group), the regular icosahedron 3,5 (H3 reflection group), and the regular four-dimensional polytope 3,3,5 (H4 reflection group). These quasicrystals exhibiting five-fold symmetry can b...
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