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Erbium Oxide
Erbium(III) oxide is the inorganic compound with the formula . It is a pink paramagnetic solid. It finds uses in various optical materials. Structure Erbium(III) oxide has a cubic structure resembling the bixbyite motif. The Er3+ centers are octahedral. Reactions The formation of erbium oxide is accomplished by burning erbium metal. Erbium oxide is insoluble in water and soluble in mineral acids. Er2O3 does not readily absorb moisture and carbon dioxide from the atmosphere. It can react with acids to form the corresponding erbium(III) salts. For example, with hydrochloric acid, the oxide follows the following idealized reaction leading to erbium chloride: : In practice, such simple acid-base reactions are accompanied by hydration: : Properties One interesting property of erbium oxides is their ability to up convert photons. Photon upconversion takes place when infrared or visible radiation, low energy light, is converted to ultraviolet or violet radiation higher energy l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cubic Crystal System
In crystallography, the cubic (or isometric) crystal system is a crystal system where the Crystal_structure#Unit_cell, unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties of these crystals: *Primitive cubic (abbreviated ''cP'' and alternatively called simple cubic) *Body-centered cubic (abbreviated ''cI'' or bcc) *Face-centered cubic (abbreviated ''cF'' or fcc, and alternatively called Close-packing_of_equal_spheres, ''cubic close-packed'' or ccp) Each is subdivided into other variants listed below. Although the ''unit cells'' in these crystals are conventionally taken to be cubes, the primitive_cell, primitive unit cells often are not. Bravais lattices The three Bravais lattices in the cubic crystal system are: The primitive cubic lattice (cP) consists of one Lattice_(group), lattice point on each corner of the cube; this means each simple cubic unit cell has in total one latt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon Upconversion
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always move at the speed of light in vacuum, (or about ). The photon belongs to the class of bosons. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, Planck proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explain the photoelectric effect, Einste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles James (chemist)
Charles James (27 April 1880 – 10 December 1928) was a chemist of British origin working in the United States. He became a professor and head of the chemistry department at the New Hampshire College of Agriculture and the Mechanic Arts (now the University of New Hampshire) in Durham, New Hampshire, US. James developed the James method for the separation and identification of rare-earth elements by fractional precipitation and crystallization, and provided extracted elements to researchers worldwide. James was one of the first scientists to identify element 71, later named lutetium, and believed that he had found the final rare earth element 61, later named promethium. In 1999 the American Chemical Society recognized Charles James's work in chemical separations as a National Historic Chemical Landmark. Early life Charles James was born on 27 April 1880 to William James and Mary Diana Shatford-James at Earls Barton near Broughton, Northamptonshire. His father died when he was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georges Urbain
Georges Urbain (12 April 1872 – 5 November 1938) was a French chemist, a professor of the Sorbonne, a member of the Institut de France, and director of the Institute of Chemistry in Paris. Much of his work focused on the rare earths, isolating and separating elements such as europium and gadolinium, and studying their spectra, their magnetic properties and their atomic masses. He discovered the element lutetium (atomic number 71). He also studied the efflorescence of saline hydrates. Education After attending the Lycée Charlemagne and Lycée Lavoisier, Urbain studied at the École supérieure de physique et de chimie industrielles de la ville de Paris (ESPCI ParisTech). He graduated as the top student in the school's ninth graduating class, in 1894. At that time he also earned his "licence ès physique et chimie" at the Sorbonne. Urbain served in teaching positions at the Préparateur at the École de Physique et Chimie Industrielle (1894-1895), in Charles Friedel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Gustaf Mosander
Carl Gustaf Mosander (10 September 1797 – 15 October 1858) was a Swedish chemist. He discovered the rare earth elements lanthanum, erbium and terbium. Early life and education Born in Kalmar, Mosander attended school there until he moved to Stockholm with his mother in 1809. In Stockholm, he became an apprentice at the ''Ugglan'' pharmacy. He took his pharmacy examination in 1817, but had an interest in medicine and joined the Karolinska Institute in 1820. He passed his medical examination in 1825. He worked in the laboratory of Jöns Jakob Berzelius and became a close friend of fellow student Friedrich Wöhler. Career In 1832 Jöns Jakob Berzelius retired in favor of his student Carl Gustaf Mosander who succeeded him as professor of chemistry and pharmacy in the Karolinska Institute. From 1845 Mosander was also a professor at and inspector for the Pharmaceutical Institute. Mosander was an assistant curator of the mineralogical collections of the Swedish Museum of Natu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fuel
Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing and sustaining nuclear fission. The three most relevant fissile isotopes are uranium-233, uranium-235 and plutonium-239. When the unstable nuclei of these atoms are hit by a slow-moving neutron, they frequently split, creating two daughter nuclei and two or three more neutrons. In that case, the neutrons released go on to split more nuclei. This creates a self-sustaining chain reaction that is controlled in a nuclear reactor, or uncontrolled in a nuclear weapon. Alternatively, if the nucleus absorbs the neutron without splitting, it creates a heavier nucleus with one additional neutron. The processes involved in mining, refining, purifying, using, and disposing of nuclear fuel are collectively known as the nuclear fuel cycle. Not all typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Poison
In applications such as nuclear reactors, a neutron poison (also called a neutron absorber or a nuclear poison) is a substance with a large neutron absorption cross-section. In such applications, absorbing neutrons is normally an undesirable effect. However, neutron-absorbing materials, also called poisons, are intentionally inserted into some types of reactors in order to lower the high reactivity of their initial fresh fuel load. Some of these poisons deplete as they absorb neutrons during reactor operation, while others remain relatively constant. The capture of neutrons by short half-life fission products is known as reactor poisoning; neutron capture by long-lived or stable fission products is called reactor slagging. Transient fission product poisons Some of the fission products generated during nuclear reactions have a high neutron absorption capacity, such as xenon-135 (microscopic cross-section σ = 2,000,000 barns (b); up to 3 million barns in reactor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material. Despite bei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erbium
Erbium is a chemical element with the symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare-earth element The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silve ..., originally found in the gadolinite mine in Ytterby, Sweden, which is the source of the element's name. Erbium's principal uses involve its pink-colored Er3+ ions, which have optical fluorescent properties particularly useful in certain laser applications. Erbium-doped glasses or crystals can be used as optical amplification media, where Er3+ ions are optically pumped at around 980 or and then radiate light at in stimulated emission. This process results in an unusually mechanically simple la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erbium Chloride
Erbium(III) chloride is a violet solid with the formula . It is used in the preparation of erbium metal. Preparation Anhydrous erbium(III) chloride can be produced by the ammonium chloride route. In the first step, erbium(III) oxide is heated with ammonium chloride to produce the ammonium salt of the pentachloride: : In the second step, the ammonium chloride salt is converted to the trichloride by heating in a vacuum at 350-400 ºC: : Structural data Erbium(III) chloride forms crystals of the type, with monoclinic crystals and the point group ''C''2/m. Erbium(III) chloride hexahydrate also forms monoclinic crystals with the point group of ''P''2/''n'' (''P''2/''c'') - ''C''42h. In this compound, erbium is octa-coordinated to form ions with the isolated completing the structure. Optical properties Erbium(III) chloride solutions show a negative nonlinear absorption effect. Catalytic properties The use of erbium(III) chloride as a catalyst has been demonstrated in the acy ... [...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. |
Bixbyite
Bixbyite is a manganese iron oxide mineral with chemical formula: (Mn,Fe)2O3. The iron/manganese ratio is quite variable and many specimens have almost no iron. It is a metallic dark black with a Mohs hardness of 6.0 - 6.5. It is a somewhat rare mineral sought after by collectors as it typically forms euhedral isometric crystals exhibiting various cubes, octahedra, and dodecahedra. It is commonly associated with beryl, quartz, spessartine, hematite, pseudobrookite, hausmannite, braunite and topaz in pneumatolytic or hydrothermal veins and cavities and in metamorphic rocks. It can also be found in lithophysal cavities in rhyolite. Typical localities are Jhabua and Chhindwara districts, India and the Thomas Range in Juab County, Utah. It is also reported from San Luis Potosi, Mexico; northern Patagonia, Argentina; Girona, Catalonia, Spain; Sweden, Germany, Namibia, Zimbabwe, and South Africa. Bixbyite was named for the American mineralogist Maynard Bixby (1853–1935), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
