"of chemical suppliers. It is used as a source of zirconium for other salts, as an analytical standard, or as a preservative. Zirconium nitrate and nitronium pentanitratozirconate can be used as chemical vapour deposition precursors as they are volatile, and decompose above 100 °C to form zirconia. At 95°C zirconium nitrate sublimes with a pressure of 0.2 mm of Hg and can be deposited as zirconium dioxide on silicon at 285°C. It has the advantage in that it is a single source, meaning it does not have to be mixed with other materials like oxygen, and decomposes at a relatively"
"Zirconium dioxide Zirconium dioxide (), sometimes known as zirconia (not to be confused with zircon), is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the mineral baddeleyite. A dopant stabilized cubic structured zirconia, cubic zirconia, is synthesized in various colours for use as a gemstone and a diamond simulant. Zirconia is produced by calcining zirconium compounds, exploiting its high thermal stability. Three phases are known: monoclinic below 1170 °C, tetragonal between 1170 °C and 2370 °C, and cubic above 2370 °C. The trend is for higher symmetry at higher temperatures, as"
"Zirconium Zirconium is a chemical element with symbol Zr and atomic number 40. The name ""zirconium"" is taken from the name of the mineral zircon (the word is related to Persian ""zargun"" (zircon;""zar-gun"", ""gold-like"" or ""as gold"")), the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Zirconium forms a variety of inorganic and organometallic compounds such as zirconium dioxide and zirconocene"
"40. The name of zirconium is taken from the mineral ""zircon"". Its atomic mass is 91.224. It is a lustrous, gray-white, strong transition metal that resembles titanium. Zirconium is mainly used as a refractory and opacifier, although minor amounts are used as alloying agent for its strong resistance to corrosion. Zirconium is obtained mainly from the mineral zircon, which is the most important form of zirconium in use. Zirconium forms a variety of inorganic and organometallic compounds such as zirconium dioxide and zirconocene dichloride, respectively. Five isotopes occur naturally, three of which are stable. Zirconium compounds have no biological role."
"zirconium to reversibly form bonds to carbon. Most complexes of Zr(II) are derivatives of zirconocene, one example being (CMe)Zr(CO). The zirconium-containing mineral zircon and related minerals (jargoon, hyacinth, jacinth, ligure) were mentioned in biblical writings. The mineral was not known to contain a new element until 1789, when Klaproth analyzed a jargoon from the island of Ceylon (now Sri Lanka). He named the new element Zirkonerde (zirconia). Humphry Davy attempted to isolate this new element in 1808 through electrolysis, but failed. Zirconium metal was first obtained in an impure form in 1824 by Berzelius by heating a mixture of potassium"
"Zirconium hydride Zirconium hydride describes an alloy made by combining zirconium and hydrogen. Hydrogen acts as a hardening agent, preventing dislocations in the zirconium atom crystal lattice from sliding past one another. Varying the amount of hydrogen and the form of its presence in the zirconium hydride (precipitated phase) controls qualities such as the hardness, ductility, and tensile strength of the resulting zirconium hydride. Zirconium hydride with increased hydrogen content can be made harder and stronger than zirconium, but such zirconium hydride is also less ductile than zirconium. Zirconium is found in the Earth's crust only in the form of"
"Cubic zirconia Cubic zirconia (CZ) is the cubic crystalline form of zirconium dioxide (ZrO). The synthesized material is hard, optically flawless and usually colorless, but may be made in a variety of different colors. It should not be confused with zircon, which is a zirconium silicate (ZrSiO). It is sometimes erroneously called ""cubic zirconium"". Because of its low cost, durability, and close visual likeness to diamond, synthetic cubic zirconia has remained the most gemologically and economically important competitor for diamonds since commercial production began in 1976. Its main competitor as a synthetic gemstone is a more recently cultivated material, synthetic"
"of Mines in Congo, 10% of its population relies in the income from diamonds. Therefore, it is argued that in the short term diamonds substituents could be an alternative to reduce conflict around the market of diamond mining but a long term solution would be establish a more rigorous system of identifying the origin of these stones. Cubic zirconia Cubic zirconia (CZ) is the cubic crystalline form of zirconium dioxide (ZrO). The synthesized material is hard, optically flawless and usually colorless, but may be made in a variety of different colors. It should not be confused with zircon, which is"
"Zircon Zircon ( or ) is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate, and its corresponding chemical formula is ZrSiO. A common empirical formula showing some of the range of substitution in zircon is (Zr, REE)(SiO)(OH). Zircon forms in silicate melts with large proportions of high field strength incompatible elements. For example, hafnium is almost always present in quantities ranging from 1 to 4%. The crystal structure of zircon is tetragonal crystal system. The natural color of zircon varies between colorless, yellow-golden, red, brown, blue and green. Colorless specimens that show gem quality"
"Zirconium(IV) silicate Zirconium silicate, also zirconium orthosilicate, ZrSiO, is a chemical compound, a silicate of zirconium. It occurs in nature as zircon, a silicate mineral. Powdered zirconium silicate is also known as zircon flour. Zirconium silicate is usually colorless, but impurities induce various colorations. It is insoluble in water, acids, alkali and aqua regia. Hardness is 7.5 on the Mohs scale. Zirconium silicate occurs in nature as mineral zircon. Ore is mined from natural deposits and concentrated by various techniques. It is separated from sand by electrostatic and electromagnetic methods. Also, the compound can be made by fusion of SiO"
"into the diamond lattice as isolated atoms (or small atomic clusters) during the diamond growth. By 2008, those elements are nitrogen, boron, hydrogen, silicon, phosphorus, nickel, cobalt and perhaps sulfur. Manganese and tungsten have been unambiguously detected in diamond, but they might originate from foreign inclusions. Detection of isolated iron in diamond has later been re-interpreted in terms of micro-particles of ruby produced during the diamond synthesis. Oxygen is believed to be a major impurity in diamond, but it has not been spectroscopically identified in diamond yet. Two electron paramagnetic resonance centers (OK1 and N3) have been assigned to nitrogen–oxygen"
"jewellery. Like diamond, cubic zirconia has a cubic crystal structure and a high index of refraction. Visually discerning a good quality cubic zirconia gem from a diamond is difficult, and most jewellers will have a thermal conductivity tester to identify cubic zirconia by its low thermal conductivity (diamond is a very good thermal conductor). This state of zirconia is commonly called ""cubic zirconia"", ""CZ"", or ""zircon"" by jewellers, but the last name is not chemically accurate. Zircon is actually the mineral name for naturally occurring zirconium silicate (ZrSiO). Zirconium dioxide Zirconium dioxide (), sometimes known as zirconia (not to be"
"of such products these days. Yttrium oxide is used to stabilize the Zirconia in late-generation porcelain-free metal-free dental ceramics. This is a very hard ceramic used as a strong base material in some full ceramic restorations. The zirconia used in dentistry is zirconium oxide which has been stabilized with the addition of yttrium oxide. The full name of zirconia used in dentistry is ""yttria-stabilized zirconia"" or YSZ. Yttrium oxide is also used to make yttrium iron garnets, which are very effective microwave filters. YO is used to make the high temperature superconductor YBaCuO, known as ""1-2-3"" to indicate the ratio"
"is prepared from diamond powder of about 25 micrometers size. The grains are coated by physical vapor deposition with 10 nanometers thick layer of alloy of tungsten with 26% rhenium, forming a tungsten carbide layer that assists bonding, then coated with 100 nanometers of copper to avoid carbide oxidation, then compacted in a mold and infiltrated with molten copper-silver alloy. Adding 55 vol.% of diamond yields material with thermal expansion matching that of gallium arsenide; slightly higher amount of diamond allows matching to silicon. Copper can be used instead of copper-silver alloy, but the higher melting point may cause partial"
"fewer Zr(III) compounds are known, and Zr(II) is very rare. The most common oxide is zirconium dioxide, ZrO, also known as ""zirconia"". This clear to white-coloured solid has exceptional fracture toughness and chemical resistance, especially in its cubic form. These properties make zirconia useful as a thermal barrier coating, although it is also a common diamond substitute. Zirconium monoxide, ZrO, is also known and S-type stars are recognised by detection of its emission lines in the visual spectrum. Zirconium tungstate has the unusual property of shrinking in all dimensions when heated, whereas most other substances expand when heated. Zirconyl chloride"
"Zirconocene Zirconocene is a hypothetical compound with 14 valence electrons, which has not been observed or isolated until now. It is an organometallic compound consisting of two cyclopentadienyl rings bound on a central zirconium atom. A crucial question in research is what kind of ligands can be used to stabilize the CpZr metallocene fragment to make it available for further reactions in organic synthesis. In contrast to the sandwich compound ferrocene with the cyclopentadienyl rings bound on opposite sides of a central metal atom, zirconocene and other group 4 metallocenes are bent. Without stabilizing ligands, the CpZr fragment is unstable"
"known adverse effects for normal, incidental ingestion. Zirconium(IV) silicate Zirconium silicate, also zirconium orthosilicate, ZrSiO, is a chemical compound, a silicate of zirconium. It occurs in nature as zircon, a silicate mineral. Powdered zirconium silicate is also known as zircon flour. Zirconium silicate is usually colorless, but impurities induce various colorations. It is insoluble in water, acids, alkali and aqua regia. Hardness is 7.5 on the Mohs scale. Zirconium silicate occurs in nature as mineral zircon. Ore is mined from natural deposits and concentrated by various techniques. It is separated from sand by electrostatic and electromagnetic methods. Also, the compound"
"Zirconocene dichloride Zirconocene dichloride is an organozirconium compound composed of a zirconium central atom, with two cyclopentadienyl and two chloro ligands. It is a colourless diamagnetic solid that is somewhat stable in air. Zirconocene dichloride may be prepared from zirconium(IV) chloride-THF complex and sodium cyclopentadienide: The closely related compound CpZrBr was first described by Birmingham and Wilkinson. The compound is a bent metallocene: the Cp rings are not parallel, the average Cp(centroid)-M-Cp angle being 128°. The Cl-Zr-Cl angle of 97.1° is wider than in niobocene dichloride (85.6°) and molybdocene dichloride (82°). This trend helped to establish the orientation of the"
"and synthetically challenging organic structures can be realized by novel C-C coupling of nitriles. Zirconocene Zirconocene is a hypothetical compound with 14 valence electrons, which has not been observed or isolated until now. It is an organometallic compound consisting of two cyclopentadienyl rings bound on a central zirconium atom. A crucial question in research is what kind of ligands can be used to stabilize the CpZr metallocene fragment to make it available for further reactions in organic synthesis. In contrast to the sandwich compound ferrocene with the cyclopentadienyl rings bound on opposite sides of a central metal atom, zirconocene and"
"Zirconia alumina Zirconia alumina is commonly used as a sand-blasting medium. It is typically used as an abrasive in casting and foundry processes. Zirconia alumina is a mixture of zirconium dioxide and aluminium oxide. Zirconia toughened alumina typically consists of alumina with a 10 to 20 percent zirconia concentration, which enhances the toughness of the alumina. To achieve the increase in the composite’s strength, a process known as stress induced transformation toughening takes place. Stress induced transformation toughening results in uniform internal strain, which causes the zirconia structure to crack, and the zirconia particles to switch phases. Because of this"
"about 5.8 ppm of the Earth's upper crust by mass. It does not exist as a free element on Earth, but is found combined in solid solution with zirconium in natural zirconium compounds such as zircon, ZrSiO, which usually has about 1–4% of the Zr replaced by Hf. Rarely, the Hf/Zr ratio increases during crystallization to give the isostructural mineral hafnon (Hf,Zr)SiO, with atomic Hf > Zr. An obsolete name for a variety of zircon containing unusually high Hf content is ""alvite"". A major source of zircon (and hence hafnium) ores is heavy mineral sands ore deposits, pegmatites, particularly in"
"from all diamond simulants, primarily by visual inspection. The most common diamond simulants are high-leaded glass (i.e., rhinestones) and cubic zirconia (CZ), both artificial materials. A number of other artificial materials, such as strontium titanate and synthetic rutile have been developed since the mid-1950s, but these are no longer in common use. Introduced at the end of the 20th century, the lab-grown product moissanite has gained popularity as an alternative to diamond. The high price of gem-grade diamonds, as well as significant ethical concerns of the diamond trade, have created a large demand for diamond simulants. In order to be"
"them with diamonds. Much more recently (tens to hundreds of million years ago), they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites. Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gas by chemical vapor deposition (CVD). Imitation diamonds can also be made out of materials such as cubic zirconia and silicon carbide. Natural, synthetic and imitation diamonds are most commonly distinguished using optical techniques or thermal conductivity measurements. Diamond is a solid form of pure carbon with its atoms arranged in a"
"phase switch, the amount of zirconia particles increases and creates stresses within the alumina’s structure. These stresses effectively heal the crack and block further cracking—the added zirconia doubles the composite’s strength and enhances toughness between two and four times. Zirconia alumina Zirconia alumina is commonly used as a sand-blasting medium. It is typically used as an abrasive in casting and foundry processes. Zirconia alumina is a mixture of zirconium dioxide and aluminium oxide. Zirconia toughened alumina typically consists of alumina with a 10 to 20 percent zirconia concentration, which enhances the toughness of the alumina. To achieve the increase in"
"the most common. It is released as a product of U, mainly in nuclear plants and during nuclear weapons tests in the 1950s and 1960s. It has a very long half-life (1.53 million years), its decay emits only low energy radiations, and it is not considered as highly hazardous. Zirconium Zirconium is a chemical element with symbol Zr and atomic number 40. The name ""zirconium"" is taken from the name of the mineral zircon (the word is related to Persian ""zargun"" (zircon;""zar-gun"", ""gold-like"" or ""as gold"")), the most important source of zirconium. It is a lustrous, grey-white, strong transition metal"
"zircon. Because of the chemical similarity, up to 5% of the zirconium in zircon is replaced by hafnium. The largest producers of the group 4 elements are Australia, South Africa and Canada. Titanium metal and its alloys have a wide range of applications, where the corrosion resistance, the heat stability and the low density (light weight) are of benefit. The foremost use of corrosion-resistant hafnium and zirconium has been in nuclear reactors. Zirconium has a very low and hafnium has a high thermal neutron-capture cross-section. Therefore, zirconium (mostly as zircaloy) is used as cladding of fuel rods in nuclear reactors,"
"one of several common elements, most synthetic garnets are composed of uncommon rare-earth elements. They are the only diamond simulants (aside from rhinestones) with no known natural counterparts: gemologically they are best termed ""artificial"" rather than ""synthetic"", because the latter term is reserved for human-made materials that can also be found in nature. Although a number of artificial garnets were successfully grown, only two became important as diamond simulants. The first was yttrium aluminium garnet (YAG; YAlO) in the late 1960s. It was (and still is) produced by the Czochralski, or crystal-pulling, process, which involves growth from the melt. An"
"Zirconia Toughened Alumina Zirconia toughened alumina is a ceramic material comprising alumina and zirconia. It is a composite ceramic material with zirconia grains in the alumina matrix. It is also known in industry as ZTA. Zirconia aluminia (or zirconia toughened alumina), a combination of zirconium oxide and aluminum oxide, is part of a class of composite ceramics called AZ composites. Noted for their mechanical properties, AZ composites are commonly used in structural applications, as cutting tools, and in many medical applications. Additionally, AZ composites feature high strength, fracture toughness, elasticity, hardness, and wear resistance. Zirconia toughened alumina (ZTA), in particular,"
"Organozirconium chemistry Organozirconium compounds are organometallic compounds containing a carbon to zirconium chemical bond. Organozirconium chemistry is the corresponding science exploring properties, structure and reactivity of these compounds. In general organozirconium compounds are stable and non-toxic. They are used in organic chemistry as an intermediate in the synthesis of chemical compounds and share characteristics with organotitanium compounds also a Group 4 element. Organozirconium compounds have been widely studied, in part because they are useful catalysts in Ziegler-Natta polymerization. The first organozirconium compound discovered (1953) was zirconocene dibromide, belongs to the metallocene family. It was prepared in a reaction of the"
"the site says that some partner sales locations will be added in 2019. Synthetic diamond A synthetic diamond (also known as a laboratory-grown diamond, cultured diamond, or cultivated diamond) is a diamond produced by a controlled process, as contrasted with a natural diamond created by geological processes or an imitation diamond made of non-diamond material that appears similar to a diamond. Synthetic diamond is also widely known as HPHT diamond or CVD diamond, after the two common production methods (referring to the high-pressure high-temperature and chemical vapor deposition crystal formation methods, respectively). While the term ""synthetic"" may sometimes be associated"
"natural and synthetic diamond. Because they occur independently at many places across the surface of a growing film or coating, they tend to produce an analog of a cobblestone street with the cobbles being nodules or clusters of sp bonded carbon. Depending upon the particular ""recipe"" being used, there are cycles of deposition of carbon and impact or continuous proportions of new carbon arriving and projectiles conveying the impacts needed to force the formation of the sp bonds. As a result, ""ta-C"" may have the structure of a cobblestone street, or the nodules may ""melt together"" to make something more"
"give one η2-butene ligand, eliminating the other butyl ligand as butane. Zirconocene dichloride Zirconocene dichloride is an organozirconium compound composed of a zirconium central atom, with two cyclopentadienyl and two chloro ligands. It is a colourless diamagnetic solid that is somewhat stable in air. Zirconocene dichloride may be prepared from zirconium(IV) chloride-THF complex and sodium cyclopentadienide: The closely related compound CpZrBr was first described by Birmingham and Wilkinson. The compound is a bent metallocene: the Cp rings are not parallel, the average Cp(centroid)-M-Cp angle being 128°. The Cl-Zr-Cl angle of 97.1° is wider than in niobocene dichloride (85.6°) and molybdocene"
"natural diamond. Every diamond contains atoms other than carbon in concentrations detectable by analytical techniques. Those atoms can aggregate into macroscopic phases called inclusions. Impurities are generally avoided, but can be introduced intentionally as a way to control certain properties of the diamond. Growth processes of synthetic diamond, using solvent-catalysts, generally lead to formation of a number of impurity-related complex centers, involving transition metal atoms (such as nickel, cobalt or iron), which affect the electronic properties of the material. For instance, pure diamond is an electrical insulator, but diamond with boron added is an electrical conductor (and, in some cases,"