Single crystal

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Single crystal" – news · newspapers · books · scholar · JSTOR (February 2010) (Learn how and when to remove this message)

Crystallization
Fundamentals
Crystal Crystal structure Nucleation
Concepts
Crystallization Crystal growth Recrystallization Seed crystal Protocrystalline Single crystal
Methods and technology
Boules Bridgman–Stockbarger method Van Arkel–de Boer process Czochralski method Epitaxy Flux method Fractional crystallization Fractional freezing Hydrothermal synthesis Kyropoulos method Laser-heated pedestal growth Micro-pulling-down Shaping processes in crystal growth Skull crucible Verneuil method Zone melting
v t e

In materials science, a single crystal (or single-crystal solid or monocrystalline solid) is a material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample, with no grain boundaries.^[1] The absence of the defects associated with grain boundaries can give monocrystals unique properties, particularly mechanical, optical and electrical, which can also be anisotropic, depending on the type of crystallographic structure.^[2] These properties, in addition to making some gems precious, are industrially used in technological applications, especially in optics and electronics.^[3]

Because entropic effects favor the presence of some imperfections in the microstructure of solids, such as impurities, inhomogeneous strain and crystallographic defects such as dislocations, perfect single crystals of meaningful size are exceedingly rare in nature.^[2] The necessary laboratory conditions often add to the cost of production. On the other hand, imperfect single crystals can reach enormous sizes in nature: several mineral species such as beryl, gypsum and feldspars are known to have produced crystals several meters across.^{[citation needed]}

The opposite of a single crystal is an amorphous structure where the atomic position is limited to short-range order only.^[4] In between the two extremes exist polycrystalline, which is made up of a number of smaller crystals known as crystallites, and paracrystalline phases.^[5] Single crystals will usually have distinctive plane faces and some symmetry, where the angles between the faces will dictate its ideal shape. Gemstones are often single crystals artificially cut along crystallographic planes to take advantage of refractive and reflective properties.^[5]