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Mercury(II) Selenide
Mercury selenide (HgSe; sometimes mercury(II) selenide) is a chemical compound of mercury and selenium. It is a grey-black crystalline solid semi-metal with a sphalerite structure. The lattice constant is 0.608 nm. HgSe occurs naturally as the mineral Tiemannite, and is a component of the "intimate mixture" of HgSe and Se known as HgSe2. Along with other II-VI compounds, colloidal nanocrystals of HgSe can be formed. Applications * Selenium is used in filters in some steel plants to remove mercury from exhaust gases. The solid product formed is HgSe. * HgSe can be used as an ohmic contact to wide-gap II-VI semiconductors such as zinc selenide or zinc oxide Zinc oxide is an inorganic compound with the Chemical formula, formula . It is a white powder which is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, Zinc metabolism, food supplements, rubbe .... Toxicity Toxic hydrogen selenide fumes can be evolved on expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphalerite
Sphalerite is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in Sedimentary exhalative deposits, sedimentary exhalative, Carbonate-hosted lead-zinc ore deposits, Mississippi-Valley type, and Volcanogenic massive sulfide ore deposit, volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfide mineral, sulfides), calcite, dolomite (mineral), dolomite, quartz, rhodochrosite, and fluorite. German geologist Ernst Friedrich Glocker discovered sphalerite in 1847, naming it based on the Greek word ''sphaleros'', meaning "deceiving", due to the difficulty of identifying the mineral. In addition to zinc, sphalerite is an ore of cadmium, gallium, germanium, and indium. Miners have been known to refer to sphalerite as ''zinc blende'', ''black-jack'', and ''ruby blende''. Marmatite is an opaque black variety with a high iron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-metal
A semimetal is a material with a small energy overlap between the bottom of the Electrical conduction, conduction Electronic band structure, band and the top of the valence band, but they do not overlap in momentum space. According to Band theory, electronic band theory, solids can be classified as Insulator (electricity), insulators, semiconductors, semimetals, or metals. In insulators and semiconductors the filled valence band is separated from an empty conduction band by a band gap. For insulators, the magnitude of the band gap is larger (e.g., > 4 Electronvolt, eV) than that of a semiconductor (e.g., < 4 eV). Because of the slight overlap between the conduction and valence bands, semimetals have no band gap and a small density of states at the Fermi level. A metal, by contrast, has an appreciable density of states at the Fermi level because the conduction band is partially filled. Temperature dependency The insulating/semiconducting st ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury(II) Compounds
Mercury most commonly refers to: * Mercury (planet), the closest planet to the Sun * Mercury (element), a chemical element * Mercury (mythology), a Roman deity Mercury or The Mercury may also refer to: Companies * Mercury (toy manufacturer), a brand of diecast toy cars manufactured in Italy * Mercury Communications, a British telecommunications firm set up in the 1980s * Mercury Corporation, an American aircraft manufacturer * Mercury Cyclecar Company, a defunct American car company * Mercury Drug, a Philippine pharmacy chain * Mercury Energy, an electricity generation and retail company in New Zealand * Mercury Filmworks, a Canadian independent animation studio * Mercury General, a multiple-line American insurance organization * Mercury Interactive, a software testing tools vendor * Mercury Marine, a manufacturer of marine engines, particularly outboard motors * Mercury Systems, a defense-related information technology company * Mercury Technologies, a financial tec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Selenide
Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic selenium compoundhttp://www.epa.gov/ttnatw01/hlthef/selenium.html, US Environmental Protection Agency, Air Toxins website with an exposure limit of 0.05 ppm over an 8-hour period.https://www.cdc.gov/niosh/docs/81-123/pdfs/0336.pdf Occupational Health Guideline for Hydrogen Selenide, The National Institute for Occupational Safety and Health, 1978 Even at extremely low concentrations, this compound has a very irritating smell resembling that of decayed horseradish or "leaking gas", but smells of rotten eggs at higher concentrations. Structure and properties H2Se adopts a bent structure with a H−Se−H bond angle of 91°. Consistent with this structure, three IR-active vibrational bands are observed: 2358, 2345, and 1034 cm−1. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Oxide
Zinc oxide is an inorganic compound with the Chemical formula, formula . It is a white powder which is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, Zinc metabolism, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically. History Early humans probably used zinc compounds in processed and unprocessed forms, as paint or medicinal ointment; however, their composition is uncertain. The use of ''pushpanjan'', probably zinc oxide, as a salve for eyes and open wounds is mentioned in the Indian medical text the Charaka Samhita, thought to date from 500 BC or before. Zinc oxide ointment is also mentioned by the Greek physician Dioscorides (1st century AD). Galen suggested treatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colloidal Nanocrystals
Blinking colloidal nanocrystals is a phenomenon observed during studies of single colloidal nanocrystals that show that they randomly turn their photoluminescence on and off even under continuous light illumination. This has also been described as luminescence intermittency. Similar behavior has been observed in crystals made of other materials. For example, porous silicon also exhibits this affect. Colloidal nanocrystals Colloidal nanocrystals are a new class of optical materials that essentially constitute a new form of matter that can be considered as "artificial atoms." Like atoms, they have discrete optical energy spectra that are tunable over a wide range of wavelengths. The desired behavior and transmission directly correlates to their size. To change the emitted wavelength, the crystal is grown larger or smaller. Their electronic and optical properties can be controlled by this method. For example, to change the emission from one visible wavelength to another simply use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiemannite
Tiemannite is a mineral, mercury selenide, formula HgSe. It occurs in hydrothermal veins associated with other selenides, or other mercury minerals such as cinnabar, and often with calcite. Discovered in 1855 in Germany, it is named after Johann Carl Wilhelm Tiemann (1848–1899). See also *List of minerals *List of minerals named after people This is a list of minerals named after people. The chemical composition of the mineral follows the name. A * Abelsonite: – American physicist Philip Hauge Abelson (1913–2004) * Abswurmbachite: – German mineralogist Irmgard Abs-Wurmbac ... References * Tiemannite from a micro-disseminated gold deposit in Qiongmo, Liu Jiajun, Zheng Minghua, Liu Jianming, Lu Wenquan, Journal of Chengdu Institute of Technology, vol. 23 (2), pages 21–28 (1996) * Timanite and onofrite in ores of Siberian mercury deposits, Vasil'yev V.I., Lavrent'yev Y.G., Doklady (Academy of Sciences of the USSR, Earth Sciences Section) vol. 222, Pages 159-162 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lattice Constant
A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has only one lattice constant, the distance between atoms, but, in general, lattices in three dimensions have six lattice constants: the lengths ''a'', ''b'', and ''c'' of the three cell edges meeting at a vertex, and the angles ''α'', ''β'', and ''γ'' between those edges. The crystal lattice parameters ''a'', ''b'', and ''c'' have the dimension of length. The three numbers represent the size of the unit cell, that is, the distance from a given atom to an identical atom in the same position and orientation in a neighboring cell (except for very simple crystal structures, this will not necessarily be distance to the nearest neighbor). Their SI unit is the meter, and they are traditionally specified in angstroms (Å); an angstrom being 0.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word ''crystal'' derives from the Ancient Greek word (), meaning both "ice" and " rock crystal", from (), "icy cold, frost". Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury Oxide
Mercury oxide can refer to: * Mercury(I) oxide (mercurous oxide), Hg2O * Mercury(II) oxide (mercuric oxide), HgO See also *Montroydite, the mineral form of mercury(II) oxide {{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenium
Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pure ore compounds in Earth's crust. Selenium ( ) was discovered in 1817 by , who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). Selenium is found in :Sulfide minerals, metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been mostly replaced with silicon semiconductor devices. Selenium is still used in a few types of Direct current, DC power surge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (element)
Mercury is a chemical element; it has Symbol (chemistry), symbol Hg and atomic number 80. It is commonly known as quicksilver. A Heavy metal element, heavy, silvery d-block element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by Mill (grinding), grinding natural cinnabar or synthetic mercuric sulfide. Exposure to mercury and mercury-containing organic compounds is toxic to the nervous system, immune system and kidneys of humans and other animals; mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury) either directly or through mechanisms of biomagnification. Mercu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
