A single crystal is a crystalline solid in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample. The opposite of a single crystal sample is a polycrystalline sample, which is made up of a number of smaller crystals known as crystallites. Because of a variety of entropic effects on the microstructure of solids, including the distorting effects of impurities and the mobility of crystallographic defects and dislocations, single crystals of meaningful size are exceedingly rare in nature, and can also be difficult to produce in the laboratory under controlled conditions. Quartz crystal A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extending in all three spatial dimensions. ... A solid is a state of matter, characterized by a definite volume and a definite shape (i. ... In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... A crystallite is a domain of solid-state matter that has the same structure as a single crystal. ... The thermodynamic entropy S, often simply called the entropy in the context of thermodynamics, is a measure of the amount of energy in a physical system that cannot be used to do work. ... Definition Impurities (im- + pure + -ity + -s) refer to any substances inside a confined amount of liquid or gas, or a piece of solid, that its chemical composition is different to the majority materials. ... Crystalline solids have a very regular atomic structure: that is, the local positions of atoms with respect to each other are repeated at the atomic scale. ... For the syntaxic operation, see Dislocation (syntax) For the medical term, see Dislocation (medicine) In materials science a dislocation is a linear crystallographic defect, or irregularity, in crystal structure. ...

Because grain boundaries can have significant effects on the physical and electrical properties of a material, single crystals are of interest to industry, and have important industrial applications. The most notable of these is the use of single crystal silicon in the fabrication of semiconductors. On the quantum scale that microprocessors operate on, the presence of grain boundaries would have a significant impact on the functionality of field effect transistors by altering local electrical properties. Therefore, microprocessor fabricators have invested heavily in facilities to produce large single crystals of silicon. A crystallite is a domain of solid-state matter that has the same structure as a single crystal. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... Nasas Glenn Research Center clean room. ... Fig. ... Microprocessors, including an Intel 80486DX2 and an Intel 80386 A microprocessor (abbreviated as µP or uP) is an electronic computer central processing unit (CPU) made from miniaturized transistors and other circuit elements on a single semiconductor integrated circuit (IC) (aka microchip or just chip). ... The field-effect transistor (FET) is a transistor that relies on an electric field to control the shape and hence the conductivity of a channel in a semiconductor material. ...

Fabrication of single crystals usually involves the building of a crystal layer by layer of atoms. Techniques to produce large single crystals (boules) include slowly drawing a rotating "seed crystal" in a molten bath of feeder material (as in the Czochralski process), and the Bridgeman technique. Some thin film deposition techniques can be used for epitaxy, forming a new layer of material with the same structure on the surface of an existing single crystal. A boule is a term used to describe a single crystal ingot produced by synthetic means. ... A seed crystal is a small piece of single crystal material from which a large crystal of, usually, the same material is to be grown. ... The Czochralski process is a method of crystal growth used to obtain single crystals of semiconductors, metals (e. ... The Bridgeman technique is a method of growing single crystal ingots or boules. ... Epitaxy is the growth of crystals of one material on the crystal face of another material, such that the crystalline substrates of both materials have the same structural orientation. ...

Turbine blades of some gas turbines are made of single crystal cast superalloy. WWII era steam turbine used for ship propulsion. ... This machine has a single-stage radial compressor and turbine, a recuperator, and foil bearings. ... Casting is a process by which a material is introduced into a mold while it is liquid, allowed to solidify in the shape inside the mold, and then removed producing a fabricated object, part, or casing. ... Superalloy, or high-performance alloy, is an alloy with superior mechanical strength, good surface stability, corrosion resistance, and can withstand high temperatures without oxidizing or losing mechanical properties. ...