Boron nitride (BN) is a binary chemical compound, consisting of equal proportions of boron and nitrogen. The empirical formula is therefore BN. Boron nitride is isoelectronic to the elemental forms of carbon and isomorphism occurs between the two species. That is boron nitride possess three polymorphic forms; one analogous to diamond, one analogous to graphite and ones analogous to the fullerenes. The diamond-like allotrope of boron nitride is one of the hardest materials known but is softer than materials such as diamond, ultrahard fullerite, and aggregated diamond nanorods. A binary compound is a chemical compound consisting of only atoms of two different elements, e. ... General Name, Symbol, Number boron, B, 5 Chemical series metalloids Group, Period, Block 13, 2, p Appearance black/brown Standard atomic weight 10. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... In chemistry, the empirical formula of a chemical compound is a simple expression of the relative number of each type of atom (called a chemical element) in it. ... Two or more molecular entities (atoms, molecules, ions) are described as isoelectronic if they have the same number of valence electrons and the same structure (number and connectivity of atoms), but may differ in the elements involved. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Standard atomic weight 12. ... In mathematics, an isomorphism (in Greek isos = equal and morphe = shape) is a kind of mapping between objects, devised by Eilhard Mitscherlich, which shows a relation between two properties or operations. ... This article is about the gemstone. ... Graphite (named by Abraham Gottlob Werner in 1789 from the Greek γραφειν (graphein): to draw/write, for its use in pencils) is one of the allotropes of carbon. ... Buckminsterfullerene (C60) Fullerenes are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube. ... This article is about the gemstone. ... Scratch caused by ultrahard fullerite on diamond Ultrahard fullerite (C60) is a form of carbon found to be harder than diamond, and which can be used to create even harder materials, such as aggregated diamond nanorods. ... Aggregated diamond nanorods, or ADNRs, are an allotrope of carbon believed to be the least compressible material known to humankind, as measured by its isothermal bulk modulus; aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), while a conventional diamond has a modulus of 442 GPa. ...

Polymorphs

Boron nitride can be used to make crystals that are extremely hard, near diamond's, and the similarity of this compound to diamond extends to other applications. Like diamond, boron nitride acts as an electrical insulator but is an excellent conductor of heat. This article is about the gemstone. ... This article or section is in need of attention from an expert on the subject. ...

Like carbon, boron nitride exists in another polymorph that has structural and lubricating qualities similar to graphite. This form of boron nitride is composed of layers of fused hexagonal sheets (analogous to graphite). These sheets (unlike those in graphite) are in register. This means that layers are placed directly upon one another such that a viewer looking down onto the structure would view only the top layer. The polar B-N bonds interfere with electron transfer so that boron nitride in this form is not an electrical conductor (in contrast to graphite which is a semimetal that conducts electricity through a network of pi bonds in the plane of its hexagonal sheets). In general, a polymorph is something that can exist in several states or forms. ... Lubrication occurs when opposing surfaces are completely separated by a lubricant film. ... Graphite (named by Abraham Gottlob Werner in 1789 from the Greek γραφειν (graphein): to draw/write, for its use in pencils) is one of the allotropes of carbon. ... Together with the metals and nonmetals, the metalloids (in Greek metallon = metal and eidos = sort - also called semimetals) form one of the three categories of chemical elements as classified by ionization and bonding properties. ...

Boron nitride nanotubes can also be constructed analogously to carbon nanotubes. An electronic device known as a diode can be formed by joining two nanoscale carbon tubes with different electronic properties. ... 3D model of three types of single-walled carbon nanotubes. ...

Image File history File links Size of this preview: 800 × 395 pixelsFull resolution (1100 × 543 pixel, file size: 323 KB, MIME type: image/png) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Size of this preview: 800 × 448 pixelsFull resolution (1100 × 616 pixel, file size: 275 KB, MIME type: image/png) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Size of this preview: 714 × 600 pixelsFull resolution (1100 × 924 pixel, file size: 636 KB, MIME type: image/png) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Sphalerite sample Another sphalerite sample The unit cell of sphalerite Sphalerite (ZnS) is a gay mineral that is the chief ore of zinc. ... Image File history File links Size of this preview: 726 × 600 pixelsFull resolution (1100 × 909 pixel, file size: 488 KB, MIME type: image/png) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Zinc sulfide is a chemical compound with the formula ZnS. Zinc sulfide is a white to yellow colored powder or crystal. ...

Cubic boron nitride

The diamond-like allotrope of boron nitride, known as cubic boron nitride, c-BN, β-BN, or z-BN (after zinc blende crystalline structure), is widely used as an abrasive for industrial tools. Such usefulness is derived from the insolubility of boron nitride in iron, nickel and related alloys at high temperatures (unlike diamond). Like diamond, it has good thermal conductivity, caused by phonons; this is a difference against metals, where the mediators are electrons. In contact with oxygen at high temperatures, BN forms a passivation layer of boron oxide. This article is about the gemstone. ... Sphalerite sample Another sphalerite sample Sphalerite (ZnS) is a mineral that is the chief ore of zinc. ... Abrasives are extremely commonplace and are used very extensively in a wide variety of industrial, domestic, and technological applications. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Standard atomic weight 58. ... An alloy is a combination, either in solution or compound, of two or more elements, at least one of which is a metal, and where the resultant material has metallic properties. ... Normals modes of vibration progression through a crystal. ... Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. ...

Commercial products are known eg. under names Borazon (by General Electric Corporation), and Elbor or Cubonite (by Russian vendors).

A crystal modification of boron nitride is w-BN, the superhard hexagonal phase of the wurzite structure. It occurs at high pressures.

Polycrystalline c-BN (PcBN) is used for wear applications. It is superior to diamond in applications requiring high temperatures in oxidizing atmosphere, and contact with iron and its alloys; c-BN abrasives are therefore used for machining steel, while diamond abrasives are preferred for aluminium alloys, ceramics, and stone. This article is about the gemstone. ...

Boron nitride binds well with metals, due to formation of interlayers of metal borides or nitrides. Materials with cubic boron nitride crystals are often used in the tool bits of cutting tools. Ceramic binders can be used as well. A tool bit generally refers to a plain High Speed Steel (HSS) tool. ... a Cutting Tool, in the context of Metalworking is any tool that is used to remove metal from the workpiece by means of shear deformation. ...

For grinding applications, softer binders, e.g. resin, porous ceramics, and soft metals, are used.

Sintered cubic boron nitride can be used in electronics as an electrically insulating heatsink material. A large copper heatsink. ...

Cubic boron nitride is produced by treating hexagonal boron nitride at high pressure and temperature, much as synthetic diamond is produced from graphite. Direct conversion of hexagonal boron nitride to the cubic form occurs at pressures up to 18 GPa and temperatures between 1730-3230 °C; addition of small amount of boron oxide can lower the required pressure to 4-7 GPa and temperature to 1500 °C. Industrially, BN conversion using catalysts is used instead; the catalyst materials differ for different production methods, eg. lithium, potassium, or magnesium, their nitrides, their fluoronitrides, water with ammonium compounds, or hydrazine. Other industrial synthesis methods use crystal growth in temperature gradient, or explosive shock wave. The shock wave method is used to produce material called heterodiamond, a superhard compound of boron, carbon, and nitrogen. A colourless synthetic diamond produced via chemical vapour deposition Synthetic diamond is diamond produced through chemical or physical processes in a factory. ... Introduction The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. ... Heterodiamond is a new superhard material containing boron, carbon, and nitrogen (BCN). ...

Low-pressure deposition of thin films of cubic boron nitride is possible. For selective etching of the deposited hexagonal phase during chemical vapor deposition, boron trifluoride is used (cf. use of atomic hydrogen for selective etching of graphite during deposition of diamond films). Ion beam deposition, Plasma Enhanced CVD, pulsed laser deposition, reactive sputtering, and other physical vapor deposition methods are used as well. DC plasma (violet) enhances the growth of carbon nanotubes in this laboratory-scale PECVD apparatus. ... Boron trifluoride is the chemical compound with the formula BF3. ... Ion Beam Deposition is a process of applying materials to a target through the application of an ion beam. ... Chemical vapor deposition (CVD) is a chemical process for depositing thin films of various materials. ... Pulsed laser deposition is a thin film deposition technique. ... Physical vapor deposition (PVD) is a technique used to deposit thin films of various materials onto various surfaces (e. ...

Hexagonal boron nitride

The graphite-like allotrope of boron nitride, known as hexagonal boron nitride, h-BN, α-BN, or g-BN (graphitic BN), and sometimes called white graphite, is useful as both a very low temperature and high-temperature lubricant (up to 900 °C in oxidizing atmosphere) and/or in situations where the electrical conductivity or chemical reactivity of graphite would be problematic. As the lubricity mechanism does not involve water molecules trapped between the layers, boron nitride lubricants can be used even in vacuum, e.g. for space applications. Graphite (named by Abraham Gottlob Werner in 1789 from the Greek γραφειν (graphein): to draw/write, for its use in pencils) is one of the allotropes of carbon. ... A lubricant (colloquially, lube, although this may also refer to personal lubricants) is a substance (usually a liquid) introduced between two moving surfaces to reduce the friction and wear between them. ...

Due to higher electronegativity of the nitrogen atoms, the electrons that in graphite form a delocalized system, are concentrated around nitrogen atoms, sequestered outside the conductivity band, therefore not playing role in conductivity nor absorbing visible light. Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ...

h-BN can be included in ceramics, alloys, resins, plastics, rubbers and other materials, giving them self-lubricating properties. Such materials are suitable for construction of e.g. bearings. Plastics filled with BN have decreased thermal expansion, increased thermal conductivity, increased electrical insulation properties, and cause reduced wear to adjacent parts. Bearing is the following: Often, bearing is the state of having something as a quality, characteristic, or permanent attribute. ...

Hexagonal boron nitride is stable in temperatures up to 1000 °C in air, 1400 °C in vacuum, and 2800 °C in inert gas. It has one of the best thermal conductivities of all electric insulators. It is fairly chemically inert and is not wetted by many melted materials (e.g. aluminium, copper, zinc, iron and steels, germanium, silicon, boron, cryolite, glass and halide salts). h-BN parts can be made by hot-pressing with subsequent machining; due to the mechanical hardness similar to graphite, the machining cost is low. The parts are made from boron nitride powders, using boron oxide as a sintering agent. Wetting of different fluids. ... Boron oxide is a colourless or white solid, also known as Diboron trioxide, formula B2O3. ... This article or section does not cite its references or sources. ...

Addition of boron nitride to silicon nitride ceramics improves the thermal shock resistance of the resulting material. For the same purpose, BN is added also to silicon nitride-alumina and titanium nitride-alumina ceramics. Other materials being reinforced with BN are e.g. alumina and zirconia, borosilicate glasses, glass ceramics, enamels, and composite ceramics with titanium boride-boron nitride and titanium boride-aluminium nitride-boron nitride and silicon carbide-boron nitride composition. Silicon nitride (Si3N4) is hard, solid substance, that can be obtained by direct reaction between silicon and nitrogen in high temperatures. ... Thermal shock and thermal loading refer to the disfuntion (and perhaps, crack) of a material due to the heating, especially non-stationary and non-uniform. ... Aluminium oxide (or aluminum oxide) (Al2O3) is a chemical compound of aluminium and oxygen. ... TiN coated drill Dark gray TiCN coating on a Gerber pocketknife Titanium nitride (TiN) is an extremely hard (~85 Rockwell C Hardness or ~2500 Vickers Hardness)1, ceramic material, often used as a coating on titanium alloy, steel, carbide, and aluminum components to improve the substrates surface properties. ... Zirconia (ZrO2) is a white crystalline oxide of zirconium. ... It has been suggested that Kimax be merged into this article or section. ... Glass-ceramic is a mixture of glass and ceramic materials (mainly lithium-, silicon-, or aluminium-oxides) yielding a material that is impervious to even extreme temperature shocks. ... In a discussion of art technology, enamel (or vitreous enamel, or porcelain enamel in American English) is the colorful result of fusion of powdered glass to a substrate through the process of firing, usually between 750 and 850 degrees Celsius. ... Titanium Diboride (chemical formula TiB2) is an extremely hard ceramic material (33GPa) with excellent corrosion resistance at high temperatures and very good wear resistance which does not occur naturally in earth. ... Aluminium nitride (AlN) is an extremely wide bandgap semiconductor material which has potential application for deep ultraviolet optoelectronics. ... Silicon carbide (SiC) is a ceramic compound of silicon and carbon that is manufactured on a large scale for use mainly as an abrasive but also occurs in nature as the extremely rare mineral moissanite. ...

Due to its excellent dielectric and insulating properties, BN is used in electronics e.g. as a substrate for semiconductors, microwave-transparent windows, structural material for seals, electrodes and catalyst carriers in fuel cells and batteries. A fuel cell is an electrochemical device similar to a battery, but differing from the latter in that it is designed for continuous replenishment of the reactants consumed; i. ...

Fine-grained h-BN is used in some cosmetics, paints, dental cements, pencil leads, etc. For other uses, see Cosmetic. ... This article does not cite its references or sources. ... This article is about the handwriting instrument. ...

Hexagonal boron nitride is produced by the nitridation or ammonolysis of boron trioxide. Thin films of boron nitride can be obtained by chemical vapor deposition from boron trichloride and nitrogen precursors. Industrial production is based on two reactions: melted boric acid with ammonia, and boric acid or alkaline borates with urea, guanidine, melamin, or other suitable organic nitrogen compounds in nitrogen atmosphere. Combustion of boron powder in nitrogen plasma at 5500 °C is used for production of ultrafine boron nitride for lubricants and toners. Boron oxide is one of the oxides of boron. ... DC plasma (violet) enhances the growth of carbon nanotubes in this laboratory-scale PECVD apparatus. ... This article is in need of attention from an expert on the subject. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... A plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation. ... A color toner bottle Toner is a powder used in laser printers and photocopiers to form the text and images on the printed paper. ...

Boron nitride fibers

Hexagonal BN can be prepared in the form of fibers, structurally similar to carbon fibers, sometimes called white carbon fiber. Two of the main methods of their synthesis are thermal decomposition of extruded borazine fibers with addition of boron oxide in nitrogen at 1800 °C, and thermal decomposition of cellulose fibers impregnated with boric acid or ammonium tetraborate in the mixture of ammonia and nitrogen above 1000 °C. Carbon fiber composite is a strong, light and very expensive material. ... Borazine is an inorganic compound composed of the elements boron, nitrogen and hydrogen. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... Cellulose as polymer of β-D-glucose Cellulose in 3D Cellulose (C6H10O5)n is a polysaccharide of beta-glucose. ... Boric acid, also called boracic acid or orthoboric acid or Acidum Boricum, is a mild acid often used as an antiseptic, insecticide, flame retardant, in nuclear power plants to control the fission rate of uranium, and as a precursor of other chemical compounds. ...

Boron nitride fibers are used as reinforcement in composite materials, with the matrix materials ranging from organic resins to ceramics to metals (see Metal matrix composites). A cloth of woven carbon fiber filaments, a common element in composite materials Composite materials (or composites for short) are engineered materials made from two or more constituent materials with significantly different physical or chemical properties and which remain separate and distinct within the finished structure. ... A metal matrix composite (MMC) is a type of composite material with at least two constituent parts, one being a metal. ...

Boron nitride nanotubes

Boron nitride nanotubes (BNNT) have been prepared, and like BN fibers, show promise for aerospace applications where integration of boron and in particular the light isotope of boron (¹⁰B) into structural materials improves their radiation-shielding properties, due to ¹⁰B's neutron absorption properties. Such ¹⁰BN materials are of particular theoretical value as composite structural material in future manned interplanetary spacecraft, where absorption-shielding from cosmic ray spallation neutrons is expected to be a particular asset in light construction materials.[1]

Amorphous boron nitride

Layers of amorphous boron nitride (a-BN) are used in some semiconductor devices, eg. MISFETs. They can be prepared by chemical decomposition of trichloroborazine with caesium, or by thermal chemical vapor deposition methods. Thermal CVD can be also used for deposition of h-BN layers, or at high temperatures, c-BN. Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium and gallium arsenide. ... MISFET [1] is the acronym used to describe Metal-Insulator Semiconductor Field Effect Transistors. ... General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Atomic mass 132. ... DC plasma (violet) enhances the growth of carbon nanotubes in this laboratory-scale PECVD apparatus. ...

Rhombohedral boron nitride

Rhombohedral boron nitride is similar to hexagonal boron nitride. It is formed transitionally during conversion of cubic BN to hexagonal form.

Other allotropes

The fullerene-like allotropes of boron nitride can be synthesized and resemble those of carbon. The recently discovered boron nitride nanotubes are an important development due to their homogeneous electronic behavior. That is, tubes of different chiralities are all semiconductor materials with the same (approximate) band gap. The fullerenes, discovered in 1985 by researchers at Rice University, are a family of carbon allotropes named after Richard Buckminster Fuller and are sometimes called buckyballs. ... Look up Nanotube in Wiktionary, the free dictionary. ... The term chiral (pronounced ) is used to describe an object which is non-superimposable on its mirror image. ... Semiconductor materials are insulators at absolute zero temperature that conduct electricity in a limited way at room temperature (see also Semiconductor). ...

See also

• Beta carbon nitride
• Borazon
• Boron phosphide
• Boron suboxide
• Aluminium nitride
• Wide bandgap semiconductors

A diagram of (β-C3N4) Beta carbon nitride (β-C3N4) is a theoretical material, derived from theories on crystalline structure. ... Borazon is the third hardest substance that is artificially produced, preceded by aggregated diamond nanorods and man-made diamonds, respectively. ... This article lacks information on the importance of the subject matter. ... Boron suboxide (chemical formula B6O) is a solid compound of boron and oxygen. ... Aluminium nitride (AlN) is an extremely wide bandgap semiconductor material which has potential application for deep ultraviolet optoelectronics. ... Wide Bandgap Semiconductors have applications in optoelectronic and power devices. ...

External links

• National Pollutant Inventory: Boron and Compounds
• Fiz Chemie Berlin thermophysical database
• Materials Safety Data Sheet at University of Oxford

• Links to external chemical sources