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Nickel Silicide
Nickel silicides include several intermetallic compounds of nickel and silicon. Nickel silicides are important in microelectronics as they form at junctions of nickel and silicon. Additionally thin layers of nickel silicides may have application in imparting surface resistance to nickel alloys. Compounds Nickel silicides include Ni3Si, Ni31Si12, Ni2Si, Ni3Si2, NiSi and NiSi2. Ni31Si12, Ni2Si, and NiSi have congruent melting points; the others form via a peritectic transformation. The silicides can be made via fusion or solid state reaction between the elements, diffusion at a junction of the two elements, and other methods including ion beam mixing. Properties Nickel silicides are generally chemically and thermally stable. They have low electrical resistivity; with NiSi 10.5–18 μΩ·cm, Ni2Si 24–30 μΩ·cm, NiSi2 34–50 μΩ·cm; nickel-rich silicides have higher resistivity rising to 90–150 μΩ·cm in Ni31Si12. Uses Microelectronics Nickel silicides are important i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Press
The CRC Press, LLC is an American publishing group that specializes in producing technical books. Many of their books relate to engineering, science and mathematics. Their scope also includes books on business, forensics and information technology. CRC Press is now a division of Taylor & Francis, itself a subsidiary of Informa. History The CRC Press was founded as the Chemical Rubber Company (CRC) in 1903 by brothers Arthur, Leo and Emanuel Friedman in Cleveland, Ohio, based on an earlier enterprise by Arthur, who had begun selling rubber laboratory aprons in 1900. The company gradually expanded to include sales of laboratory equipment to chemists. In 1913 the CRC offered a short (116-page) manual called the ''Rubber Handbook'' as an incentive for any purchase of a dozen aprons. Since then the ''Rubber Handbook'' has evolved into the CRC's flagship book, the '' CRC Handbook of Chemistry and Physics''. In 1964, Chemical Rubber decided to focus on its publishing ventures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogenation
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a Catalysis, catalyst such as nickel, palladium or platinum. The process is commonly employed to redox, reduce or Saturated and unsaturated compounds, saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule, often an alkene. Catalysts are required for the reaction to be usable; non-catalytic hydrogenation takes place only at very high temperatures. Hydrogenation reduces Double bond, double and Triple bond, triple bonds in hydrocarbons. Process Hydrogenation has three components, the Saturated and unsaturated compounds, unsaturated substrate, the hydrogen (or hydrogen source) and, invariably, a catalyst. The redox, reduction reaction is carried out at different temperatures and pressures depending upon the substrate and the activity of the catalyst. Related or competing reactions The same ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transition Metal Silicides
Transition or transitional may refer to: Mathematics, science, and technology Biology * Transition (genetics), a point mutation that changes a purine nucleotide to another purine (A ↔ G) or a pyrimidine nucleotide to another pyrimidine (C ↔ T) * Transitional fossil, any fossilized remains of a lifeform that exhibits the characteristics of two distinct taxonomic groups * A phase during childbirth contractions during which the cervix completes its dilation Gender and sex * Gender transitioning, the process of changing one's gender presentation to accord with one's internal sense of one's gender – the idea of what it means to be a man or woman * Sex reassignment therapy, the physical aspect of a gender transition Physics * Phase transition, a transformation of the state of matter; for example, the change between a solid and a liquid, between liquid and gas or between gas and plasma * Quantum phase transition, a phase transformation between different quantum phases * Quantu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel Compounds
Nickel compounds are chemical compounds containing the element nickel which is a member of the group 10 of the periodic table. Most compounds in the group have an oxidation state of +2. Nickel is classified as a transition metal with nickel(II) having much chemical behaviour in common with iron(II) and cobalt(II). Many salts of nickel(II) are isomorphous with salts of magnesium due to the ionic radii of the cations being almost the same. Nickel forms many coordination complexes. Nickel tetracarbonyl was the first pure metal carbonyl produced, and is unusual in its volatility. Metalloproteins containing nickel are found in biological systems. Nickel forms simple binary compounds with non metals including halogens, chalcogenides, and pnictides. Nickel ions can act as a cation in salts with many acids, including common oxoacids. Salts of the hexaaqua ion (Ni2+) are especially well known. Many double salts containing nickel with another cation are known. There are organic acid salts. N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salicide
The term salicide refers to a technology used in the microelectronics industry used to form electrical contacts between the semiconductor device and the supporting interconnect structure. The salicide process involves the reaction of a metal thin film with silicon in the active regions of the device, ultimately forming a metal silicide contact through a series of annealing and/or etch processes. The term "salicide" is a compaction of the phrase self-aligned silicide. The description "self-aligned" suggests that the contact formation does not require photolithography patterning processes, as opposed to a non-aligned technology such as polycide. The term salicide is also used to refer to the metal silicide formed by the contact formation process, such as "titanium salicide", although this usage is inconsistent with accepted naming conventions in chemistry. Contact Formation The salicide process begins with deposition of a thin transition metal layer over fully formed and pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium Disilicide
Titanium disilicide ( Ti Si2) is an inorganic chemical compound of titanium and silicon. Preparation Titanium disilicide can be obtained from the reaction between titanium or titanium hydride with silicon. :Ti + 2 Si → TiSi2 It is also possible to prepare it aluminothermically by the ignition of aluminium powder, sulfur, silicon dioxide, and titanium dioxide or potassium hexafluorotitanate, K2TiF6, by electrolysis of a melt of potassium hexafluorotitanate and titanium dioxide, or by reaction of titanium with silicon tetrachloride. Another method is the reaction of titanium tetrachloride with silane, dichlorosilane or silicon. :TiCl4 + 2 SiH4 → TiSi2 + 4 HCl + 2 H2 :TiCl4 + 2 SiH2Cl2 + 2 H2 → TiSi2 + 8 HCl :TiCl4 + 3 Si → TiSi2 + SiCl4 Uses Titanium silicide is used in the semiconductor industry. It is typically grown by means of salicide The term salicide refers to a technology used in the microelectronics industry used to form electrical contacts between the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophoricity
A substance is pyrophoric (from grc-gre, πυροφόρος, , 'fire-bearing') if it ignites spontaneously in air at or below (for gases) or within 5 minutes after coming into contact with air (for liquids and solids). Examples are organolithium compounds and triethylborane. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen. Class D fire extinguishers are designated for use in fires involving pyrophoric materials. A related concept is hypergolicity, in which two compounds spontaneously ignite when mixed. Uses The creation of sparks from metals is based on the pyrophoricity of small metal particles, and pyrophoric alloys are made for this purpose. The sparking mechanisms in lighters and various toys, using ferrocerium; starting fires without matches, using a firesteel; the flintlock mechanism in firearms; and spark testing ferrou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unsaturated Hydrocarbon
300px, Structure of an ethene molecule, the simplest unsaturated hydrocarbon Unsaturated hydrocarbons are hydrocarbons that have double or triple covalent bonds between adjacent carbon atoms. The term "unsaturated" means more hydrogen atoms may be added to the hydrocarbon to make it saturated (i.e. consisting all single bonds). The configuration of an unsaturated carbons include straight chain, such as alkenes and alkynes, as well as branched chains and aromatic compounds. Except for aromatic compounds, unsaturated hydrocarbons are mostly reactive and undergo multiple reactions to their multiple bonds. Nomenclature For the sake of clearer communication and less misunderstanding, a consistent naming system is necessary, which gives rise to the IUPAC nomenclature. Some standard steps to follow when naming unsaturated hydrocarbon molecules with IUPAC nomenclature are elaborated below. *1. Find and count the number of carbon atoms in the longest carbon chain and use the corres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stainless Steel
Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corrosion resistance, resistance to corrosion results from the chromium, which forms a Passivation (chemistry), passive film that can protect the material and self-healing material, self-heal in the presence of oxygen. The alloy's properties, such as luster and resistance to corrosion, are useful in many applications. Stainless steel can be rolled into Sheet metal, sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, vehicles, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for chemicals and food products. The biological cleanability of stainless steel is superior to both alumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearson Symbol
The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W. B. Pearson. The symbol is made up of two letters followed by a number. For example: * Diamond structure, ''cF''8 * Rutile structure, ''tP''6 The two (italicised) letters specify the Bravais lattice. The lower-case letter specifies the crystal family, and the upper-case letter the centering type. The number at the end of the Pearson symbol gives the number of the atoms in the conventional unit cell.Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005 IR-3.4.4, pp. 49–51; IR-11.5, pp. 241–242. |
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