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91-463: Cubic zirconia (abbreviated CZ ) is the cubic crystalline form of zirconium dioxide (ZrO 2 ). The synthesized material is hard 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 4 ). It is sometimes erroneously called cubic zirconium . Because of its low cost, durability, and close visual likeness to diamond , synthetic cubic zirconia has remained

182-407: A diamond simulant and jewel competitor, can potentially reduce demand for conflict diamonds , and impact the controversy surrounding the rarity and value of diamonds. Regarding value, the paradigm that diamonds are costly due to their rarity and visual beauty has been replaced by an artificial rarity attributed to price-fixing practices of De Beers Company which held a monopoly on the market from

273-420: A protective coating on particles of titanium dioxide pigments, as a refractory material, in insulation , abrasives , and enamels . Stabilized zirconia is used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. This high ionic conductivity (and a low electronic conductivity) makes it one of

364-510: A " rare-earth element ". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. Y is the only stable isotope and the only isotope found in the Earth's crust . The most important present-day use of yttrium is as a component of phosphors , especially those used in LEDs . Historically, it was once widely used in

455-419: A conventional feldspathic porcelain for aesthetic reasons, or of strong, extremely durable dental prostheses constructed entirely from monolithic zirconia, with limited but constantly improving aesthetics. Zirconia stabilized with yttria (yttrium oxide), known as yttria-stabilized zirconia , can be used as a strong base material in some full ceramic crown restorations. Transformation-toughened zirconia

546-411: A film of diamond-like carbon (DLC) is one such innovation, a process using chemical vapor deposition . The resulting material is purportedly harder, more lustrous and more like diamond overall. The coating is thought to quench the excess fire of cubic zirconia, while improving its refractive index, thus making it appear more like diamond. Additionally, because of the high percentage of diamond bonds in

637-719: A heavy black rock in an old quarry near the Swedish village of Ytterby (now part of the Stockholm Archipelago ). Thinking it was an unknown mineral containing the newly discovered element tungsten , he named it ytterbite and sent samples to various chemists for analysis. Johan Gadolin at the University of Åbo identified a new oxide (or " earth ") in Arrhenius' sample in 1789, and published his completed analysis in 1794. Anders Gustaf Ekeberg confirmed

728-487: A large variety of synthetic garnets , and yttria is used to make yttrium iron garnets ( Y 3 Fe 5 O 12 , "YIG"), which are very effective microwave filters which were recently shown to have magnetic interactions more complex and longer-ranged than understood over the previous four decades. Yttrium, iron , aluminium , and gadolinium garnets (e.g. Y 3 (Fe,Al) 5 O 12 and Y 3 (Fe,Gd) 5 O 12 ) have important magnetic properties. YIG

819-499: A peculiar oxidation state of the copper atoms, which somehow leads to the superconducting behavior. The theory of low temperature superconductivity has been well understood since the BCS theory of 1957. It is based on a peculiarity of the interaction between two electrons in a crystal lattice. However, the BCS theory does not explain high temperature superconductivity, and its precise mechanism

910-462: A protective oxide ( Y 2 O 3 ) film that forms on the surface. This film can reach a thickness of 10  μm when yttrium is heated to 750 ° C in water vapor . When finely divided, however, yttrium is very unstable in air; shavings or turnings of the metal can ignite in air at temperatures exceeding 400 °C. Yttrium nitride (YN) is formed when the metal is heated to 1000 °C in nitrogen . The similarities of yttrium to

1001-426: A relatively high content of yttrium. Yttrium is not considered a "bone-seeker" like strontium and lead . Normally, as little as 0.5 milligrams (0.0077 gr) is found in the entire human body; human breast milk contains 4 ppm. Yttrium can be found in edible plants in concentrations between 20 ppm and 100 ppm (fresh weight), with cabbage having the largest amount. With as much as 700 ppm,

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1092-485: A short half-life, it exists in secular equilibrium with its long-lived parent isotope, strontium-90 ( Sr) (half-life 29 years). All group 3 elements have an odd atomic number , and therefore few stable isotopes . Scandium has one stable isotope , and yttrium itself has only one stable isotope, Y, which is also the only isotope that occurs naturally. However, the lanthanide rare earths contain elements of even atomic number and many stable isotopes. Yttrium-89

1183-560: A store of chemical energy for use with surface transportation on Mars. Carbon monoxide/oxygen engines have been suggested for early surface transportation use, as both carbon monoxide and oxygen can be straightforwardly produced by zirconia electrolysis without requiring use of any of the Martian water resources to obtain hydrogen, which would be needed for the production of methane or any hydrogen-based fuels. Zirconia can be used as photocatalyst since its high band gap (~ 5 eV) allows

1274-467: A study published in Scientific Reports . "This REY-rich mud has great potential as a rare-earth metal resource because of the enormous amount available and its advantageous mineralogical features," the study reads. The study shows that more than 16 million short tons (15 billion kilograms) of rare-earth elements could be "exploited in the near future." As well as yttrium (Y), which

1365-650: A thin shell of still-solid zirconia, with crystal growth from the melt. The process was named cold crucible , an allusion to the system of water cooling used. Though promising, these attempts yielded only small crystals. Later, Soviet scientists under V. V. Osiko in the Laser Equipment Laboratory at the Lebedev Physical Institute in Moscow perfected the technique, which was then named skull crucible (an allusion either to

1456-463: A trivalent transition metal, yttrium forms various inorganic compounds , generally in the +3 oxidation state, by giving up all three of its valence electrons . A good example is yttrium(III) oxide ( Y 2 O 3 ), also known as yttria, a six- coordinate white solid. Yttrium forms a water-insoluble fluoride , hydroxide , and oxalate , but its bromide , chloride , iodide , nitrate and sulfate are all soluble in water. The Y ion

1547-410: A very particular building material, especially in the bio-engineering industry: It has been used to make reliable super-sharp medical scalpels for doctors that are compatible with bio-tissues and contain an edge much smoother than one made of steel. In recent years manufacturers have sought ways of distinguishing their product by supposedly "improving" cubic zirconia. Coating finished cubic zirconia with

1638-1139: Is Y with a half-life of 25  ms and the most stable is Y with half-life 106.629 days. Apart from Y, Y, and Y, with half-lives of 58.51 days, 79.8 hours, and 64 hours, respectively; all other isotopes have half-lives of less than a day and most of less than an hour. Yttrium isotopes with mass numbers at or below 88 decay mainly by positron emission (proton → neutron) to form strontium ( Z = 38) isotopes. Yttrium isotopes with mass numbers at or above 90 decay mainly by electron emission (neutron → proton) to form zirconium (Z = 40) isotopes. Isotopes with mass numbers at or above 97 are also known to have minor decay paths of β delayed neutron emission . Yttrium has at least 20 metastable ("excited") isomers ranging in mass number from 78 to 102. Multiple excitation states have been observed for Y and Y. While most yttrium isomers are expected to be less stable than their ground state ; Y have longer half-lives than their ground states, as these isomers decay by beta decay rather than isomeric transition . In 1787, part-time chemist Carl Axel Arrhenius found

1729-466: Is cubic . Unlike TiO 2 , which features six-coordinated titanium in all phases, monoclinic zirconia consists of seven-coordinated zirconium centres. This difference is attributed to the larger size of the zirconium atom relative to the titanium atom. Zirconia is chemically unreactive. It is slowly attacked by concentrated hydrofluoric acid and sulfuric acid . When heated with carbon, it converts to zirconium carbide . When heated with carbon in

1820-740: Is a high-index material usable from the near-UV to the mid-IR , due to its low absorption in this spectral region. In such applications, it is typically deposited by PVD . In jewelry making, some watch cases are advertised as being "black zirconium oxide". In 2015 Omega released a fully ZrO 2 watch named "The Dark Side of The Moon" with ceramic case, bezel, pushers, and clasp, advertising it as four times harder than stainless steel and therefore much more resistant to scratches during everyday use. In gas tungsten arc welding , tungsten electrodes containing 1% zirconium oxide (a.k.a. zirconia ) instead of 2% thorium have good arc starting and current capacity, and are not radioactive. Single crystals of

1911-463: Is a key ingredient in the yttrium barium copper oxide (YBa 2 Cu 3 O 7 , aka 'YBCO' or '1-2-3') superconductor developed at the University of Alabama in Huntsville and the University of Houston in 1987. This superconductor is notable because the operating superconductivity temperature is above liquid nitrogen 's boiling point (77.1 K). Since liquid nitrogen is less expensive than

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2002-401: Is a slow neutron capture of lighter elements inside pulsating red giant stars. Yttrium isotopes are among the most common products of the nuclear fission of uranium in nuclear explosions and nuclear reactors. In the context of nuclear waste management, the most important isotopes of yttrium are Y and Y, with half-lives of 58.51 days and 64 hours, respectively. Though Y has

2093-455: Is a term to describe the coordination of a group of contiguous atoms of a ligand bound to the central atom; it is indicated by the Greek letter eta, η. Yttrium complexes were the first examples of complexes where carboranyl ligands were bound to a d -metal center through a η -hapticity. Vaporization of the graphite intercalation compounds graphite–Y or graphite– Y 2 O 3 leads to

2184-689: Is also very efficient as an acoustic energy transmitter and transducer. Yttrium aluminium garnet ( Y 3 Al 5 O 12 or YAG) has a hardness of 8.5 and is also used as a gemstone in jewelry (simulated diamond ). Cerium -doped yttrium aluminium garnet (YAG:Ce) crystals are used as phosphors to make white LEDs . YAG, yttria, yttrium lithium fluoride (LiYF 4 ), and yttrium orthovanadate (YVO 4 ) are used in combination with dopants such as neodymium , erbium , ytterbium in near- infrared lasers . YAG lasers can operate at high power and are used for drilling and cutting metal. The single crystals of doped YAG are normally produced by

2275-676: Is colorless in solution due to the absence of electrons in the d and f electron shells . Water readily reacts with yttrium and its compounds to form Y 2 O 3 . Concentrated nitric and hydrofluoric acids do not rapidly attack yttrium, but other strong acids do. With halogens , yttrium forms trihalides such as yttrium(III) fluoride ( YF 3 ), yttrium(III) chloride ( YCl 3 ), and yttrium(III) bromide ( YBr 3 ) at temperatures above roughly 200 °C. Similarly, carbon , phosphorus , selenium , silicon and sulfur all form binary compounds with yttrium at elevated temperatures. Organoyttrium chemistry

2366-436: 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(IV) silicate ( ZrSiO 4 ). Yttrium Yttrium is a chemical element ; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as

2457-462: Is converted into the oxide by heating under oxygen. By reacting the resulting yttrium oxide with hydrogen fluoride , yttrium fluoride is obtained. When quaternary ammonium salts are used as extractants, most yttrium will remain in the aqueous phase. When the counter-ion is nitrate, the light lanthanides are removed, and when the counter-ion is thiocyanate, the heavy lanthanides are removed. In this way, yttrium salts of 99.999% purity are obtained. In

2548-437: Is dependent on the phase (cubic, tetragonal, monoclinic, or amorphous) and preparation methods, with typical estimates from 5–7 eV. A special case of zirconia is that of tetragonal zirconia polycrystal , or TZP, which is indicative of polycrystalline zirconia composed of only the metastable tetragonal phase. The main use of zirconia is in the production of hard ceramics, such as in dentistry, with other uses including as

2639-427: Is emitted from the europium while the yttrium collects energy from the electron gun and passes it to the phosphor. Yttrium compounds can serve as host lattices for doping with different lanthanide cations. Tb can be used as a doping agent to produce green luminescence . As such yttrium compounds such as yttrium aluminium garnet (YAG) are useful for phosphors and are an important component of white LEDs . Yttria

2730-421: Is fed into a cold crucible. Metallic chips of either zirconium or the stabilizer are introduced into the powder mix in a compact pile manner. The RF generator is switched on and the metallic chips quickly start heating up and readily oxidize into more zirconia. Consequently, the surrounding powder heats up by thermal conduction, begins melting and, in turn, becomes electroconductive, and thus it begins to heat up via

2821-556: Is found in most rare-earth minerals , and some uranium ores , but never in the Earth's crust as a free element. About 31  ppm of the Earth's crust is yttrium, making it the 43rd most abundant element. Yttrium is found in soil in concentrations between 10 and 150 ppm (dry weight average of 23 ppm) and in sea water at 9  ppt . Lunar rock samples collected during the American Apollo Project have

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2912-609: Is generally considered brittle . Under shortwave UV cubic zirconia typically fluoresces a yellow, greenish yellow or "beige". Under longwave UV the effect is greatly diminished, with a whitish glow sometimes being seen. Colored stones may show a strong, complex rare earth absorption spectrum . Discovered in 1892, the yellowish monoclinic mineral baddeleyite is a natural form of zirconium oxide. The high melting point of zirconia (2750 °C or 4976 °F) hinders controlled growth of single crystals. However, stabilization of cubic zirconium oxide had been realized early on, with

3003-417: Is less electronegative than its predecessor in the group, scandium , and less electronegative than the next member of period 5 , zirconium . However, due to the lanthanide contraction , it is also less electronegative than its successor in the group, lutetium . Yttrium is the first d-block element in the fifth period. The pure element is relatively stable in air in bulk form, due to passivation of

3094-399: Is marketed as "mystic" by many dealers. Unlike diamond-like carbon and other hard synthetic ceramic coatings, the iridescent effect made with precious metal coatings is not durable, due to their extremely low hardness and poor abrasion wear properties, compared to the remarkably durable cubic zirconia substrate. Key features of cubic zirconia distinguish it from diamond: Cubic zirconia, as

3185-541: Is named after ytterbite , a mineral first identified in 1787 by the chemist Carl Axel Arrhenius . He named the mineral after the village of Ytterby , in Sweden , where it had been discovered. When one of the chemicals in ytterbite was later found to be a previously unidentified element, the element was then named yttrium after the mineral. Yttrium is a soft, silver-metallic, lustrous and highly crystalline transition metal in group 3 . As expected by periodic trends , it

3276-441: Is often more useful in its phase 'stabilized' state. Upon heating, zirconia undergoes disruptive phase changes. By adding small percentages of yttria, these phase changes are eliminated, and the resulting material has superior thermal, mechanical, and electrical properties. In some cases, the tetragonal phase can be metastable . If sufficient quantities of the metastable tetragonal phase is present, then an applied stress, magnified by

3367-453: Is produced by calcining zirconium compounds, exploiting its high thermostability . 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 is usually the case. A small percentage of the oxides of calcium or yttrium stabilize in the cubic phase. The very rare mineral tazheranite , (Zr,Ti,Ca)O 2 ,

3458-454: Is relatively hard, 8–8.5 on the Mohs scale —slightly harder than most semi-precious natural gems . Its refractive index is high at 2.15–2.18 (compared to 2.42 for diamonds) and its luster is Adamantine lustre . Its dispersion is very high at 0.058–0.066, exceeding that of diamond (0.044). Cubic zirconia has no cleavage and exhibits a conchoidal fracture . Because of its high hardness, it

3549-483: Is required for cubic crystals (taking on the fluorite structure ) to form, and remain stable at ordinary temperatures; typically this is either yttrium or calcium oxide, the amount of stabilizer used depending on the many recipes of individual manufacturers. Therefore, the physical and optical properties of synthesized CZ vary, all values being ranges. It is a dense substance, with a density between 5.6 and 6.0 g/cm—about 1.65 times that of diamond. Cubic zirconia

3640-558: Is the emergence of conflict diamonds. The Kimberley Process (KP) was established to deter the illicit trade of diamonds that fund civil wars in Angola and Sierra Leone . However, the KP is not as effective in decreasing the number of conflict diamonds reaching the European and American markets. Its definition does not include forced labor conditions or human right violations. A 2015 study from

3731-487: Is the study of compounds containing carbon–yttrium bonds. A few of these are known to have yttrium in the oxidation state 0. (The +2 state has been observed in chloride melts, and +1 in oxide clusters in the gas phase. ) Some trimerization reactions were generated with organoyttrium compounds as catalysts. These syntheses use YCl 3 as a starting material, obtained from Y 2 O 3 and concentrated hydrochloric acid and ammonium chloride . Hapticity

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3822-433: Is thought to be more abundant than it otherwise would be, due in part to the s-process, which allows enough time for isotopes created by other processes to decay by electron emission (neutron → proton). Such a slow process tends to favor isotopes with atomic mass numbers (A = protons + neutrons) around 90, 138 and 208, which have unusually stable atomic nuclei with 50, 82, and 126 neutrons, respectively. This stability

3913-438: Is thought to result from their very low neutron-capture cross-section . Electron emission of isotopes with those mass numbers is simply less prevalent due to this stability, resulting in them having a higher abundance. Y has a mass number close to 90 and has 50 neutrons in its nucleus. At least 32 synthetic isotopes of yttrium have been observed, and these range in atomic mass number from 76 to 108. The least stable of these

4004-401: Is used as a sintering additive in the production of porous silicon nitride . Yttrium compounds are used as a catalyst for ethylene polymerization . As a metal, yttrium is used on the electrodes of some high-performance spark plugs . Yttrium is used in gas mantles for propane lanterns as a replacement for thorium , which is radioactive . Yttrium is used in the production of

4095-448: Is used as window material for the monitoring of corrosive liquids due to its chemical stability and mechanical toughness. YCZ has also been used as a substrate for semiconductor and superconductor films in similar industries. Mechanical properties of partially stabilized zirconia (high hardness and shock resistance, low friction coefficient, high chemical and thermal resistance as well as high wear and tear resistance) allow it to be used as

4186-408: Is used in products like camera lenses and mobile phone screens, the rare-earth elements found are europium (Eu), terbium (Tb), and dysprosium (Dy). As yttrium is chemically similar to lanthanides, it occurs in the same ores ( rare-earth minerals ) and is extracted by the same refinement processes. A slight distinction is recognized between the light (LREE) and the heavy rare-earth elements (HREE), but

4277-417: Is used to label drugs such as edotreotide and ibritumomab tiuxetan for the treatment of various cancers , including lymphoma , leukemia , liver, ovarian, colorectal, pancreatic and bone cancers. It works by adhering to monoclonal antibodies , which in turn bind to cancer cells and kill them via intense β-radiation from the Y (see monoclonal antibody therapy ). A technique called radioembolization

4368-418: Is used to make ceramic knives . Because of the hardness, ceramic-edged cutlery stays sharp longer than steel edged products. Due to its infusibility and brilliant luminosity when incandescent , it was used as an ingredient of sticks for limelight . Zirconia has been proposed to electrolyze carbon monoxide and oxygen from the atmosphere of Mars to provide both fuel and oxidizer that could be used as

4459-465: Is used to treat hepatocellular carcinoma and liver metastasis . Radioembolization is a low toxicity, targeted liver cancer therapy that uses millions of tiny beads made of glass or resin containing Y. The radioactive microspheres are delivered directly to the blood vessels feeding specific liver tumors/segments or lobes. It is minimally invasive and patients can usually be discharged after a few hours. This procedure may not eliminate all tumors throughout

4550-641: The Czochralski process . Small amounts of yttrium (0.1 to 0.2%) have been used to reduce the grain sizes of chromium , molybdenum , titanium , and zirconium . Yttrium is used to increase the strength of aluminium and magnesium alloys. The addition of yttrium to alloys generally improves workability, adds resistance to high-temperature recrystallization, and significantly enhances resistance to high-temperature oxidation (see graphite nodule discussion below). Yttrium can be used to deoxidize vanadium and other non-ferrous metals . Yttria stabilizes

4641-618: The Democratic Republic of Congo are that a boycott in purchases of diamonds would only worsen their economy. According to the Ministry of Mines in Congo, 10% of its population relies on the income from diamonds. Therefore, cubic zirconia are a short term alternative to reduce conflict but a long term solution would be to establish a more rigorous system of identifying the origin of these stones. Zirconium dioxide Zirconia

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4732-677: The Enough Project , showed that groups in the Central African Republic have reaped between US$ 3 million and US$ 6 million annually from conflict diamonds. UN reports show that more than US$ 24 million in conflict diamonds have been smuggled since the establishment of the KP. Diamond simulants have become an alternative to boycott the funding of unethical practices. Terms such as “Eco-friendly Jewelry” define them as conflict free origin and environmentally sustainable. However, concerns from mining countries such as

4823-474: The cubic form of zirconia in jewelry. Yttrium has been studied as a nodulizer in ductile cast iron , forming the graphite into compact nodules instead of flakes to increase ductility and fatigue resistance. Having a high melting point , yttrium oxide is used in some ceramic and glass to impart shock resistance and low thermal expansion properties. Those same properties make such glass useful in camera lenses . The radioisotope yttrium-90 ( Y)

4914-425: The lanthanides are so strong that the element has been grouped with them as a rare-earth element , and is always found in nature together with them in rare-earth minerals . Chemically, yttrium resembles those elements more closely than its neighbor in the periodic table, scandium , and if physical properties were plotted against atomic number , it would have an apparent number of 64.5 to 67.5, placing it between

5005-422: The liquid helium required for metallic superconductors, the operating costs for applications would be less. The actual superconducting material is often written as YBa 2 Cu 3 O 7– d , where d must be less than 0.7 for superconductivity. The reason for this is still not clear, but it is known that the vacancies occur only in certain places in the crystal, the copper oxide planes, and chains, giving rise to

5096-585: The phase diagram , the cubic phase will crystallize first as the solution is cooled down no matter the concentration of Y 2 O 3 . If the concentration of Y 2 O 3 is not high enough the cubic structure will start to break down into the tetragonal state which will then break down into a monoclinic phase. If the concentration of Y 2 O 3 is between 2.5-5% the resulting product will be PSZ (partially stabilized zirconia) while monophasic cubic crystals will form from around 8-40%. Below 14% at low growth rates tend to be opaque indicating partial phase separation in

5187-445: The stress concentration at a crack tip, can cause the tetragonal phase to convert to monoclinic, with the associated volume expansion. This phase transformation can then put the crack into compression, retarding its growth, and enhancing the fracture toughness . This mechanism, known as transformation toughening , significantly extends the reliability and lifetime of products made with stabilized zirconia. The ZrO 2 band gap

5278-494: The 1870s to early 2000s. The company pleaded guilty to these charges in an Ohio court in 13 July 2004. However, while De Beers has less market power, the price of diamonds continues to increase due to the demand in emerging markets such as India and China. The emergence of artificial stones such as cubic zirconia with optic properties similar to diamonds, could be an alternative for jewelry buyers given their lower price and noncontroversial history. An issue closely related to monopoly

5369-516: The RF generator as well. This continues until the entire product is molten. Due to the cooling system surrounding the crucible, a thin shell of sintered solid material is formed. This causes the molten zirconia to remain contained within its own powder which prevents it from being contaminated from the crucible and reduces heat loss. The melt is left at high temperatures for some hours to ensure homogeneity and ensure that all impurities have evaporated. Finally,

5460-596: The United States. Only a few tonnes of yttrium metal are produced each year by reducing yttrium fluoride to a metal sponge with calcium magnesium alloy. The temperature of an arc furnace , in excess of 1,600 °C, is sufficient to melt the yttrium. The red component of color television cathode ray tubes is typically emitted from an yttria ( Y 2 O 3 ) or yttrium oxide sulfide ( Y 2 O 2 S ) host lattice doped with europium (III) cation (Eu ) phosphors . The red color itself

5551-472: The amorphous diamond coating, the finished simulant will show a positive diamond signature in Raman spectra . Another technique first applied to quartz and topaz has also been adapted to cubic zirconia: An iridescent effect created by vacuum-sputtering onto finished stones an extremely thin layer of a precious metal (typically gold ), or certain metal oxides, metal nitrides, or other coatings. This material

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5642-446: The cubic phase of zirconia are commonly used as diamond simulant in 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

5733-492: The distinction is not perfect. Yttrium is concentrated in the HREE group due to its ion size, though it has a lower atomic mass . Rare-earth elements (REEs) come mainly from four sources: One method for obtaining pure yttrium from the mixed oxide ores is to dissolve the oxide in sulfuric acid and fractionate it by ion exchange chromatography . With the addition of oxalic acid , the yttrium oxalate precipitates. The oxalate

5824-413: The early 1920s, the chemical symbol Yt was used for the element, after which Y came into common use. In 1987, yttrium barium copper oxide was found to achieve high-temperature superconductivity . It was only the second material known to exhibit this property, and it was the first-known material to achieve superconductivity above the (economically important) boiling point of nitrogen. Yttrium

5915-441: The entire crucible is slowly removed from the RF coils to reduce the heating and let it slowly cool down (from bottom to top). The rate at which the crucible is removed from the RF coils is chosen as a function of the stability of crystallization dictated by the phase transition diagram. This provokes the crystallization process to begin and useful crystals begin to form. Once the crucible has been completely cooled to room temperature,

6006-791: The entire liver, but works on one segment or one lobe at a time and may require multiple procedures. Also see radioembolization in the case of combined cirrhosis and hepatocellular carcinoma. Needles made of Y, which can cut more precisely than scalpels, have been used to sever pain-transmitting nerves in the spinal cord , and Y is also used to carry out radionuclide synovectomy in the treatment of inflamed joints, especially knees, in people with conditions such as rheumatoid arthritis . A neodymium-doped yttrium–aluminium–garnet laser has been used in an experimental, robot-assisted radical prostatectomy in canines in an attempt to reduce collateral nerve and tissue damage, and erbium-doped lasers are coming into use for cosmetic skin resurfacing. Yttrium

6097-556: The formation of endohedral fullerenes such as Y@C 82 . Electron spin resonance studies indicated the formation of Y and (C 82 ) ion pairs. The carbides Y 3 C, Y 2 C, and YC 2 can be hydrolyzed to form hydrocarbons . Yttrium in the Solar System was created by stellar nucleosynthesis , mostly by the s-process (≈72%), but also the r-process (≈28%). The r-process consists of rapid neutron capture by lighter elements during supernova explosions. The s-process

6188-423: The generation of high-energy electrons and holes. Some studies demonstrated the activity of doped zirconia (in order to increase visible light absorption) in degrading organic compounds and reducing Cr(VI) from wastewaters. Zirconia is also a potential high-κ dielectric material with potential applications as an insulator in transistors . Zirconia is also employed in the deposition of optical coatings ; it

6279-417: The higher the operation temperature of an engine, the greater the possible efficiency . Another low-thermal-conductivity use is as a ceramic fiber insulation for crystal growth furnaces, fuel-cell stacks, and infrared heating systems. This material is also used in dentistry in the manufacture of subframes for the construction of dental restorations such as crowns and bridges , which are then veneered with

6370-429: The identification in 1797 and named the new oxide yttria . In the decades after Antoine Lavoisier developed the first modern definition of chemical elements , it was believed that earths could be reduced to their elements, meaning that the discovery of a new earth was equivalent to the discovery of the element within, which in this case would have been yttrium . Friedrich Wöhler is credited with first isolating

6461-400: The inability to predict the size of the crystals produced and it is impossible to control the crystallization process through temperature changes. The apparatus used in this process consists of a cup-shaped crucible surrounded by radio frequency-activated (RF-activated) copper coils and a water-cooling system. Zirconium dioxide thoroughly mixed with a stabilizer (normally 10% yttrium oxide )

6552-555: The jewelry marketplace by the Ceres Corporation, with crystals stabilized with 94% yttria. Other major producers as of 1993 include Taiwan Crystal Company Ltd , Swarovski and ICT inc. By 1980, annual global production had reached 60 million carats (12 tonnes) and continued to increase, with production reaching around 400 tonnes per year in 1998. Because the natural form of cubic zirconia is so rare, all cubic zirconia used in jewelry has been synthesized, one method of which

6643-401: The lanthanides gadolinium and erbium . It often also falls in the same range for reaction order, resembling terbium and dysprosium in its chemical reactivity. Yttrium is so close in size to the so-called 'yttrium group' of heavy lanthanide ions that in solution, it behaves as if it were one of them. Even though the lanthanides are one row farther down the periodic table than yttrium,

6734-403: The metal in 1828 by reacting a volatile chloride that he believed to be yttrium chloride with potassium. In 1843, Carl Gustaf Mosander found that samples of yttria contained three oxides: white yttrium oxide (yttria), yellow terbium oxide (confusingly, this was called 'erbia' at the time) and rose-colored erbium oxide (called 'terbia' at the time). A fourth oxide, ytterbium oxide ,

6825-547: The minds of scientists seeking a new and versatile material for use in lasers and other optical applications. Its production eventually exceeded that of earlier synthetics, such as synthetic strontium titanate , synthetic rutile , YAG ( yttrium aluminium garnet ) and GGG ( gadolinium gallium garnet). Some of the earliest research into controlled single-crystal growth of cubic zirconia occurred in 1960s France, much work being done by Y. Roulin and R. Collongues. This technique involved molten zirconia being contained within

6916-482: 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 moissanite . Cubic zirconia is crystallographically isometric , an important attribute of a would-be diamond simulant . During synthesis zirconium oxide naturally forms monoclinic crystals , which are stable under normal atmospheric conditions. A stabilizer

7007-496: The most useful electroceramics . Zirconium dioxide is also used as the solid electrolyte in electrochromic devices . Zirconia is a precursor to the electroceramic lead zirconate titanate ( PZT ), which is a high-κ dielectric, which is found in myriad components. The very low thermal conductivity of cubic phase of zirconia also has led to its use as a thermal barrier coating , or TBC, in jet and diesel engines to allow operation at higher temperatures. Thermodynamically,

7098-470: The presence of chlorine, it converts to zirconium(IV) chloride . This conversion is the basis for the purification of zirconium metal and is analogous to the Kroll process . Zirconium dioxide is one of the most studied ceramic materials. ZrO 2 adopts a monoclinic crystal structure at room temperature and transitions to tetragonal and cubic at higher temperatures. The change of volume caused by

7189-402: The red phosphors in television set cathode ray tube displays. Yttrium is also used in the production of electrodes , electrolytes , electronic filters , lasers , superconductors , various medical applications, and tracing various materials to enhance their properties. Yttrium has no known biological role. Exposure to yttrium compounds can cause lung disease in humans. The element

7280-406: The refractive index lower than 5 × 10 − 5 {\displaystyle 5\times 10^{-5}} . However some samples contain defects with the most characteristic and common ones listed below. Due to its optical properties yttrium cubic zirconia (YCZ) has been used for windows, lenses, prisms, filters and laser elements. Particularly in the chemical industry it

7371-421: The resulting crystals are multiple elongated-crystalline blocks. This shape is dictated by a concept known as crystal degeneration according to Tiller. The size and diameter of the obtained crystals is a function of the cross-sectional area of the crucible, volume of the melt and composition of the melt. The diameter of the crystals is heavily influenced by the concentration of Y 2 O 3 stabilizer. As seen on

7462-422: The seeds of woody plants have the highest known concentrations. As of April 2018 there are reports of the discovery of very large reserves of rare-earth elements in the deep seabed several hundred kilometers from the tiny Japanese island of Minami-Torishima Island , also known as Marcus Island. This location is described as having "tremendous potential" for rare-earth elements and yttrium (REY), according to

7553-697: The shape of the water-cooled container or to the form of crystals sometimes grown). They named the jewel Fianit after the institute's name FIAN (Physical Institute of the Academy of Science), but the name was not used outside of the USSR. This was known at the time as the Institute of Physics at the Russian Academy of Science. Their breakthrough was published in 1973, and commercial production began in 1976. In 1977, cubic zirconia began to be mass-produced in

7644-453: The similarity in atomic radius may be attributed to the lanthanide contraction . One of the few notable differences between the chemistry of yttrium and that of the lanthanides is that yttrium is almost exclusively trivalent , whereas about half the lanthanides can have valences other than three; nevertheless, only for four of the fifteen lanthanides are these other valences important in aqueous solution ( Ce , Sm , Eu , and Yb ). As

7735-578: The solid solution (likely due to diffusion in the crystals remaining in the high temperature region for a longer time). Above this threshold crystals tend to remain clear at reasonable growth rates and maintains good annealing conditions. Because of cubic zirconia's isomorphic capacity, it can be doped with several elements to change the color of the crystal. A list of specific dopants and colors produced by their addition can be seen below. The vast majority of YCZ (yttrium bearing cubic zirconia) crystals are clear with high optical perfection and with gradients of

7826-431: The structure transitions from tetragonal to monoclinic to cubic induces large stresses, causing it to crack upon cooling from high temperatures. When the zirconia is blended with some other oxides, the tetragonal and/or cubic phases are stabilized. Effective dopants include magnesium oxide (MgO), yttrium oxide ( Y 2 O 3 , yttria), calcium oxide ( CaO ), and cerium(III) oxide ( Ce 2 O 3 ). Zirconia

7917-441: The synthetic product stabilized zirconia introduced in 1929. Although cubic, it was in the form of a polycrystalline ceramic : it was used as a refractory material, highly resistant to chemical and thermal attack (up to 2540 °C or 4604 °F). In 1937, German mineralogists M. V. Stackelberg and K. Chudoba discovered naturally occurring cubic zirconia in the form of microscopic grains included in metamict zircon. This

8008-544: The usual situation, where yttrium is in a mixture that is two-thirds heavy-lanthanide, yttrium should be removed as soon as possible to facilitate the separation of the remaining elements. Annual world production of yttrium oxide had reached 600 tonnes (660 short tons ) by 2001; by 2014 it had increased to 6,400 tonnes (7,000 short tons). Global reserves of yttrium oxide were estimated in 2014 to be more than 450,000 tonnes (500,000 short tons). The leading countries for these reserves included Australia, Brazil, China, India, and

8099-400: Was patented by Josep F. Wenckus & Co. in 1997. The skull-melting method refined by Josep F. Wenckus and coworkers in 1997 remains the industry standard. This is largely due to the process allowing for temperatures of over 3000  °C to be achieved, lack of contact between crucible and material as well as the freedom to choose any gas atmosphere. Primary downsides to this method include

8190-572: Was isolated in 1878 by Jean Charles Galissard de Marignac . New elements were later isolated from each of those oxides, and each element was named, in some fashion, after Ytterby, the village near the quarry where they were found (see ytterbium , terbium , and erbium ). In the following decades, seven other new metals were discovered in "Gadolin's yttria". Since yttria was found to be a mineral and not an oxide, Martin Heinrich Klaproth renamed it gadolinite in honor of Gadolin. Until

8281-401: Was thought to be a byproduct of the metamictization process, but the two scientists did not think the mineral important enough to give it a formal name. The discovery was confirmed through X-ray diffraction , proving the existence of a natural counterpart to the synthetic product. As with the majority of grown diamond substitutes , the idea of producing single-crystal cubic zirconia arose in

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