Yttrium

The element 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 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.{{cite book|chapter-url = http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elements.pdf|title = The Elements|chapter=Yttrium|author = Hammond, C. R.|access-date = 2008-08-26|publisher = Fermi National Accelerator Laboratory|pages = 4–33|archive-url = https://web.archive.org/web/20080626181434/http://www-d0.fnal.gov/hardware/cal/lvps_info/engineering/elements.pdf |archive-date = June 26, 2008|url-status=dead|isbn = 978-0-04-910081-7|year = 1985}}The electronegativity of both scandium and yttrium are between europium and gadolinium. 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 a protective oxide ({{chem|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.

{{further|Rare-earth element}}

The similarities of yttrium to the lanthanides are so strong that the element has been grouped with them as a rare-earth element,{{cite book

|title=Nomenclature of Inorganic Chemistry: IUPAC Recommendations 2005

|editor=Connelly N G

|editor2=Damhus T

|editor3=Hartshorn R M

|editor4=Hutton A T

|page=51

|date=2005

|isbn=978-0-85404-438-2

|url=http://publications.iupac.org/books/rbook/Red_Book_2005.pdf

|access-date=2007-12-17

|publisher=RSC Publishing

|url-status=live

|archive-url=https://web.archive.org/web/20090304204436/http://www.iupac.org/publications/books/rbook/Red_Book_2005.pdf

|archive-date=2009-03-04

}} and is always found in nature together with them in rare-earth minerals.Emsley 2001, p. 498 Chemically, yttrium resembles those elements more closely than its neighbor in the periodic table, scandium,Daane 1968, p. 810. and if physical properties were plotted against atomic number, it would have an apparent number of 64.5 to 67.5, placing it between the lanthanides gadolinium and erbium.Daane 1968, p. 815.

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.{{harvnb|Greenwood|1997|p=945}} Even though the lanthanides are one row farther down the periodic table than yttrium, the similarity in atomic radius may be attributed to the lanthanide contraction.{{harvnb|Greenwood|1997|p=1234}}

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 (cerium, samarium, europium, and ytterbium).Daane 1968, p. 817

{{category see also|Yttrium compounds}}

File:Yttrium + carbonate.jpg

As a trivalent transition metal, yttrium forms various inorganic compounds, generally in the +3 oxidation state, by giving up all three of its valence electrons.{{harvnb|Greenwood|1997|p=948}} A good example is yttrium(III) oxide ({{chem|Y|2|O|3}}), also known as yttria, a six-coordinate white solid.{{harvnb|Greenwood|1997|p=947}}

Yttrium forms a water-insoluble fluoride, hydroxide, and oxalate, but its bromide, chloride, iodide, nitrate and sulfate are all soluble in water. The Y{{sup|3+}} ion 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 {{chem|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 ({{chem|YF|3}}), yttrium(III) chloride ({{chem|YCl|3}}), and yttrium(III) bromide ({{chem|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 is the study of compounds containing carbon–yttrium bonds. A few of these are known to have yttrium in the oxidation state 0.{{Cite encyclopedia|encyclopedia= Encyclopedia of Inorganic Chemistry|title = Scandium, Yttrium & The Lanthanides: Organometallic Chemistry|first = Herbert|last = Schumann|author2=Fedushkin, Igor L. |doi = 10.1002/0470862106.ia212|date = 2006|isbn = 978-0-470-86078-6}} (The +2 state has been observed in chloride melts,{{cite journal|title = The anomalous stabilisation of the oxidation state 2+ of lanthanides and actinides

|first1 = Mikheev|last1 = Nikolai B.|journal = Russian Chemical Reviews|volume = 61|issue = 10|date = 1992|doi = 10.1070/RC1992v061n10ABEH001011|pages = 990–998|last2 = Auerman|first2 = L. N.|last3 = Rumer|first3 = Igor A.|last4 = Kamenskaya|first4 = Alla N.|last5 = Kazakevich|first5 = M. Z.|bibcode = 1992RuCRv..61..990M | s2cid=250859394 }} and +1 in oxide clusters in the gas phase.{{cite journal|doi = 10.5012/bkcs.2005.26.2.345|title = Formation of Yttrium Oxide Clusters Using Pulsed Laser Vaporization|journal = Bull. Korean Chem. Soc.|date = 2005|volume = 26|issue = 2|pages = 345–348|first = Weekyung|last = Kang|author2 = E. R. Bernstein|doi-access = free}}) Some trimerization reactions were generated with organoyttrium compounds as catalysts. These syntheses use {{chem|YCl|3}} as a starting material, obtained from {{chem|Y|2|O|3}} and concentrated hydrochloric acid and ammonium chloride.{{Cite book|last = Turner|first = Francis M. Jr.|author2 = Berolzheimer, Daniel D.|author3 = Cutter, William P.|author4 = Helfrich, John|date = 1920|title = The Condensed Chemical Dictionary|location = New York|publisher = Chemical Catalog Company|pages = [https://archive.org/details/condchemdiction00chemrich/page/492 492]|url = https://archive.org/details/condchemdiction00chemrich|quote = Yttrium chloride.|access-date = 2008-08-12}}{{Cite book|last = Spencer|first = James F.|date = 1919|title = The Metals of the Rare Earths

|location = New York|publisher = Longmans, Green, and Co.|pages = [https://archive.org/details/metalsrareearth00spengoog/page/n151 135]|url = https://archive.org/details/metalsrareearth00spengoog

|quote = Yttrium chloride.|access-date =2008-08-12}}

Hapticity 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{{sup|0}}-metal center through a η{{sup|7}}-hapticity. Vaporization of the graphite intercalation compounds graphite–Y or graphite–{{chem|Y|2|O|3}} leads to the formation of endohedral fullerenes such as Y@C{{sub|82}}. Electron spin resonance studies indicated the formation of Y{{sup|3+}} and (C{{sub|82}}){{sup|3−}} ion pairs. The carbides Y{{sub|3}}C, Y{{sub|2}}C, and YC{{sub|2}} can be hydrolyzed to form hydrocarbons.

{{main|Isotopes of yttrium}}

Yttrium in the Solar System was created by stellar nucleosynthesis, mostly by the s-process (≈72%), but also the r-process (≈28%).{{cite journal|journal = Geochimica et Cosmochimica Acta|volume = 71|issue = 18|date = 2007|doi = 10.1016/j.gca.2007.07.010|title = Geo- and cosmochemistry of the twin elements yttrium and holmium|first = Andreas|last = Pack|author2 = Sara S. Russell|author2-link = Sara Russell|author3 = J. Michael G. Shelley|author4 = Mark van Zuilen|name-list-style = amp|pages = 4592–4608|bibcode=2007GeCoA..71.4592P}} The r-process consists of rapid neutron capture by lighter elements during supernova explosions. The s-process is a slow neutron capture of lighter elements inside pulsating red giant stars.{{harvnb|Greenwood|1997|pp=12–13}}

File:Mira 1997.jpg is an example of the type of red giant star in which most of the yttrium in the solar system was created.]]

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 {{sup|91}}Y and {{sup|90}}Y, with half-lives of 58.51 days and 64 hours, respectively. Though {{sup|90}}Y has a short half-life, it exists in secular equilibrium with its long-lived parent isotope, strontium-90 ({{sup|90}}Sr) (half-life 29 years).

All group 3 elements have an odd atomic number, and therefore few stable isotopes.{{harvnb|Greenwood|1997|p=946}} Scandium has one stable isotope, and yttrium itself has only one stable isotope, {{sup|89}}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 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).{{efn|Essentially, a neutron becomes a proton while an electron and antineutrino are emitted.}}

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.{{efn|See: magic number}} This stability 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.{{Cite book|editor = Lide, David R.|chapter = Yttrium

|date = 2007–2008|title = CRC Handbook of Chemistry and Physics|volume = 4

|page = 41|location = New York|publisher = CRC Press|isbn = 978-0-8493-0488-0}} ⁸⁹Y 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.{{cite web|url = http://www.nndc.bnl.gov/chart/|editor = Alejandro A. Sonzogni (Database Manager)|title = Chart of Nuclides|publisher = National Nuclear Data Center, Brookhaven National Laboratory|access-date = 2008-09-13|date = 2008|location = Upton, New York|archive-date = 2011-07-21|archive-url = https://web.archive.org/web/20110721051025/http://www.nndc.bnl.gov/chart/|url-status = dead}} The least stable of these is {{sup|109}}Y with a half-life of 25 ms and the most stable is {{sup|88}}Y with half-life 106.629 days.{{Cite journal |last1=Kondev |first1=F.G. |last2=Wang |first2=M. |last3=Huang |first3=W.J. |last4=Naimi |first4=S. |last5=Audi |first5=G. |date=2021-03-01 |title=The NUBASE2020 evaluation of nuclear physics properties * |journal=Chinese Physics C |volume=45 |issue=3 |pages=030001 |doi=10.1088/1674-1137/abddae |issn=1674-1137|doi-access=free |bibcode=2021ChPhC..45c0001K }} Apart from {{sup|91}}Y, {{sup|87}}Y, and {{sup|90}}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{{sup|−}} delayed neutron emission.{{NUBASE 2003}}

Yttrium has at least 20 metastable ("excited") isomers ranging in mass number from 78 to 102.{{efn|Metastable isomers have higher-than-normal energy states than the corresponding non-excited nucleus and these states last until a gamma ray or conversion electron is emitted from the isomer. They are designated by an 'm' being placed next to the isotope's mass number.}} Multiple excitation states have been observed for {{sup|80}}Y and {{sup|97}}Y. While most yttrium isomers are expected to be less stable than their ground state; {{sup|78m, 84m, 85m, 96m, 98m1, 100m, 102m}}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 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,Emsley 2001, p. 496 he named it ytterbite{{efn|Ytterbite was named after the village it was discovered near, plus the -ite ending to indicate it was a mineral.}} and sent samples to various chemists for analysis.Van der Krogt 2005

File:Johan Gadolin.jpg discovered yttrium oxide.]]

Johan Gadolin at the Royal Academy of Åbo (Turku) identified a new oxide (or "earth") in Arrhenius' sample in 1789, and published his completed analysis in 1794.Gadolin 1794{{efn|Stwertka 1998, p. 115 says that the identification occurred in 1789 but is silent on when the announcement was made. Van der Krogt 2005 cites the original publication, with the year 1794, by Gadolin.}} Anders Gustaf Ekeberg confirmed the identification in 1797 and named the new oxide yttria.{{harvnb|Greenwood|1997|p=944}} 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.{{efn|Earths were given an -a ending and new elements are normally given an -ium ending.}}{{cite journal |last1=Marshall |first1=James L. Marshall |last2=Marshall |first2=Virginia R. Marshall |title=Rediscovery of the elements: The Rare Earths–The Beginnings |journal=The Hexagon |date=2015 |pages=41–45 |url=http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/rare%20earths%20I.pdf |access-date=30 December 2019}}{{cite journal |last1=Marshall |first1=James L. Marshall |last2=Marshall |first2=Virginia R. Marshall |title=Rediscovery of the elements: The Rare Earths–The Confusing Years |journal=The Hexagon |date=2015 |pages=72–77 |url=http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/rare%20earths%20II.pdf |access-date=30 December 2019}}{{cite book |last1=Weeks |first1=Mary Elvira |title=The discovery of the elements |date=1956 |publisher=Journal of Chemical Education |location=Easton, PA |url=https://archive.org/details/discoveryoftheel002045mbp |edition=6th }}

Friedrich Wöhler is credited with first isolating the metal in 1828 by reacting a volatile chloride that he believed to be yttrium chloride with potassium.{{cite web |title=Yttrium |url=https://www.rsc.org/periodic-table/element/39/yttrium |website=The Royal Society of Chemistry |date=2020 |access-date=3 January 2020}}{{cite journal|journal = Annalen der Physik|volume = 89|issue = 8|pages = 577–582|title = Ueber das Beryllium und Yttrium|first = Friedrich|last = Wöhler|author-link = Friedrich Wöhler|doi = 10.1002/andp.18280890805|date = 1828|bibcode = 1828AnP....89..577W |url = https://zenodo.org/record/1423522}}Heiserman, David L. (1992). "Element 39: Yttrium". Exploring Chemical Elements and their Compounds. New York: TAB Books. pp. 150–152. {{ISBN|0-8306-3018-X}}.

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).{{cite book|last = Heiserman|first = David L.|title = Exploring Chemical Elements and their Compounds|location = New York|publisher = TAB Books|isbn = 978-0-8306-3018-9|chapter = Carl Gustaf Mosander and his Research on rare Earths|page = 41|date = 1992|chapter-url-access = registration|chapter-url = https://archive.org/details/exploringchemica01heis}}{{cite journal|journal=Annalen der Physik und Chemie|volume=60

|date=1843|pages=297–315|title=Ueber die das Cerium begleitenden neuen Metalle Lathanium und Didymium, so wie über die mit der Yttererde vorkommen-den neuen Metalle Erbium und Terbium

|author = Mosander, Carl Gustaf|author-link = Carl Gustaf Mosander

|issue = 2|language= de|doi = 10.1002/andp.18431361008|bibcode = 1843AnP...136..297M |url=https://zenodo.org/record/1423592

}} A fourth oxide, ytterbium oxide, was isolated in 1878 by Jean Charles Galissard de Marignac.{{cite encyclopedia|encyclopedia = Encyclopædia Britannica|date = 2005|publisher = Encyclopædia Britannica, Inc.|title=Ytterbium}} 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 the early 1920s, the chemical symbol Yt was used for the element, after which Y came into common use.{{cite journal|journal = Pure Appl. Chem.|volume = 70|issue = 1|pages = 237–257

|date = 1998|first = Tyler B.|last = Coplen|author2=Peiser, H. S. |title = History of the Recommended Atomic-Weight Values from 1882 to 1997: A Comparison of Differences from Current Values to the Estimated Uncertainties of Earlier Values (Technical Report)|doi = 10.1351/pac199870010237|s2cid = 96729044|url = https://zenodo.org/record/1236255|doi-access = free}}{{Cite journal |last=Dinér |first=Peter |date=February 2016 |title=Yttrium from Ytterby |journal=Nature Chemistry |language=en |volume=8 |issue=2 |pages=192 |doi=10.1038/nchem.2442 |pmid=26791904 |bibcode=2016NatCh...8..192D |issn=1755-4349|doi-access=free }}

In 1987, yttrium barium copper oxide was found to achieve high-temperature superconductivity. It was only the second material known to exhibit this property,{{cite journal|author = Wu, M. K.|title = Superconductivity at 93 K in a New Mixed-Phase Y-Ba-Cu-O Compound System at Ambient Pressure

|journal = Physical Review Letters|date = 1987|volume = 58|issue = 9|pages = 908–910|doi = 10.1103/PhysRevLett.58.908|pmid=10035069|bibcode=1987PhRvL..58..908W|first2 = J. R.|last2=Ashburn|last3 = Torng|first3 = C. J.|last4 = Hor|first4 = P. H.|last5 = Meng|first5 = R. L.|first6 = L.|last6=Gao|first7 = Z. J.|last7=Huang|first8 = Y. Q.|last8=Wang|first9 = C. W.|last9=Chu|display-authors = 1

|doi-access = free}} and it was the first-known material to achieve superconductivity above the (economically important) boiling point of nitrogen.{{efn|T_c for YBCO is 93 K and the boiling point of nitrogen is 77 K.}}

File:Xenotímio1.jpeg crystals contain yttrium.]]

Yttrium is found in most rare-earth minerals, and some uranium ores, but never in the Earth's crust as a free element.{{cite web|url = http://www.lenntech.com/periodic-chart-elements/y-en.htm|access-date = 2008-08-26|title = yttrium|publisher = Lenntech}} About 31 ppm of the Earth's crust is yttrium,{{cite book|title=Encyclopedia of Inorganic Chemistry|first=Simon A. |last=Cotton| doi= 10.1002/0470862106.ia211 |date= 2006-03-15|chapter=Scandium, Yttrium & the Lanthanides: Inorganic & Coordination Chemistry|isbn=978-0-470-86078-6}} making it the 43rd most abundant element.{{rp|615}} 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 a relatively high content of yttrium.Stwertka 1998, p. 115.

Yttrium is not considered a "bone-seeker" like strontium and lead.{{cite journal|journal = Journal of Biological Chemistry|date = 1952|volume = 195|pages = 837–841|title = The Skeletal Deposition of Yttrium|first = N. S.|last = MacDonald|author2 = Nusbaum, R. E.|author3 = Alexander, G. V.|pmid = 14946195|issue = 2|doi = 10.1016/S0021-9258(18)55794-X|doi-access = free}} Normally, as little as {{convert|0.5|mg}} 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, the seeds of woody plants have the highest known concentrations.

{{As of|2018|April}} 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 a study published in Scientific Reports.{{cite journal |last1=Takaya et a. |first1=Yutaro |title=The tremendous potential of deep-sea mud as a source of rare-earth elements |journal=Scientific Reports |date=10 April 2018 |volume=8 |issue=5763 |page=5763 |doi=10.1038/s41598-018-23948-5 |pmid=29636486 |pmc=5893572 |bibcode=2018NatSR...8.5763T }} "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 {{convert|16|e6ST|e9kg|abbr=off|lk=in}} of rare-earth elements could be "exploited in the near future." As well as yttrium (Y), which is used in products like camera lenses and mobile phone screens, the rare-earth elements found are europium (Eu), terbium (Tb), and dysprosium (Dy).{{Cite web | url=https://www.foxnews.com/science/treasure-island-rare-metals-discovery-on-remote-pacific-atoll-is-worth-billions-of-dollars/ | title=Treasure island: Rare metals discovery on remote Pacific atoll is worth billions of dollars| website=Fox News| date=2018-04-19}}

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 the distinction is not perfect. Yttrium is concentrated in the HREE group due to its ion size, though it has a lower atomic mass.{{cite journal|journal = European Journal of Mineralogy |date = 1991|volume = 3|issue = 4|pages = 641–650|url = http://eurjmin.geoscienceworld.org/cgi/content/abstract/3/4/641|title = The rare earths; their minerals, production and technical use|first = Giulio|last = Morteani|doi = 10.1127/ejm/3/4/0641|bibcode = 1991EJMin...3..641M|url-access = subscription}}{{cite journal|journal = Journal of Alloys and Compounds|date = 2006|volume = 408–412|pages = 1339–1343|doi = 10.1016/j.jallcom.2005.04.033|title = Rare earth minerals and resources in the world|first = Yasuo|last = Kanazawa|author2=Kamitani, Masaharu }}

File:Yttrium 1.jpg

Rare-earth elements (REEs) come mainly from four sources:{{cite journal|journal = Russian Journal of Non-Ferrous Metals|date = 2008

|volume = 49|issue = 1|pages = 14–22|title = Review of the World Market of Rare-Earth Metals

|first = A. V.|last = Naumov|url=https://link.springer.com/article/10.1007/s11981-008-1004-6|doi = 10.1007/s11981-008-1004-6

|s2cid = 135730387

|url-access = subscription}}

• Carbonate and fluoride containing ores such as the LREE bastnäsite ((Ce, La, etc.)(CO{{sub|3}})F) contain on average 0.1% yttrium compared to the 99.9% for the 16 other REEs. The main source of bastnäsite from the 1960s to the 1990s was the Mountain Pass rare earth mine in California, making the United States the largest producer of REEs during that period. The name "bastnäsite" is actually a group name, and the Levinson suffix is used in the correct mineral names, e.g., bästnasite-(Y) has Y as a prevailing element.{{Cite web|url=https://www.mindat.org/|title=Mindat.org - Mines, Minerals and More|website=www.mindat.org}}{{cite journal|journal=Elements |last1=Burke |first1=Ernst A.J. |title=The use of suffixes in mineral names |url=http://elementsmagazine.org/archives/e4_2/e4_2_dep_mineralmatters.pdf |date= 2008|volume=4|issue=2|page=96 |access-date=7 December 2019}}{{Cite web | url=http://nrmima.nrm.se/ | title=International Mineralogical Association - Commission on New Minerals, Nomenclature and Classification | access-date=2018-10-06 | archive-url=https://web.archive.org/web/20190810195707/http://nrmima.nrm.se// | archive-date=2019-08-10 | url-status=dead }}
• Monazite ((Ce, La, etc.)phosphate), which is mostly phosphate, is a placer deposit of sand created by the transportation and gravitational separation of eroded granite. Monazite as a LREE ore contains 2% (or 3%)Stwertka 1998, p. 116 yttrium. The largest deposits were found in India and Brazil in the early 20th century, making those two countries the largest producers of yttrium in the first half of that century. Of the monazite group, the Ce-dominant member, monazite-(Ce), is the most common one.{{Cite web|url=https://www.mindat.org/min-2751.html|title=Monazite-(Ce): Mineral information, data and localities.|website=www.mindat.org|access-date=2019-11-03}}
• Xenotime, a REE phosphate, is the main HREE ore containing as much as 60% yttrium as yttrium phosphate (YPO{{sub|4}}). This applies to xenotime-(Y).{{Cite web|url=https://www.mindat.org/min-4333.html|title=Xenotime-(Y): Mineral information, data and localities.|website=www.mindat.org}} The largest mine is the Bayan Obo deposit in China, making China the largest exporter for HREE since the closure of the Mountain Pass mine in the 1990s.
• Ion absorption clays or Longnan clays are the weathering products of granite and contain only 1% of REEs. The final ore concentrate can contain as much as 8% yttrium. Ion absorption clays are mostly in southern China.{{cite journal|journal = Chinese Journal of Geochemistry|date = 1996|volume = 15|issue = 4|pages = 344–352|doi = 10.1007/BF02867008|title = The behaviour of rare-earth elements (REE) during weathering of granites in southern Guangxi, China|first = Zuoping|last = Zheng|author2=Lin Chuanxian | bibcode=1996Geoch..15..344Z |s2cid = 130529468}} Yttrium is also found in samarskite and fergusonite (which also stand for group names).Emsley 2001, p. 497

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 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 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 {{convert|600|t|ST|lk=on}} by 2001; by 2014 it had increased to {{convert|7,000|ST|t|order=flip}}.{{cite web|title=Mineral Commodity Summaries|url=http://minerals.usgs.gov/minerals/pubs/commodity/rare_earths/mcs-2015-yttri.pdf|website=minerals.usgs.gov|access-date=2016-12-26}} Global reserves of yttrium oxide were estimated in 2014 to be more than {{convert|500,000|ST|t|order=flip}}. The leading countries for these reserves included Australia, Brazil, China, India, and 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.{{cite book|publisher = Walter de Gruyter|date = 1985|edition = 91–100|pages = 1056–1057|isbn = 978-3-11-007511-3|title = Lehrbuch der Anorganischen Chemie|first = Arnold F.

|last = Holleman|author2=Wiberg, Egon|author3=Wiberg, Nils}}

File:Aperture Grille.jpgs.]]

The red component of color television cathode ray tubes is typically emitted from an yttria ({{chem|Y|2|O|3}}) or yttrium oxide sulfide ({{chem|Y|2|O|2|S}}) host lattice doped with europium (III) cation (Eu{{sup|3+}}) phosphors.{{efn|Emsley 2001, p. 497 says that "Yttrium oxysulfide, doped with europium (III), was used as the standard red component in colour televisions", and Jackson and Christiansen (1993) state that 5–10 g yttrium oxide and 0.5–1 g europium oxide were required to produce a single TV screen, as quoted in Gupta and Krishnamurthy.}} The red color itself is emitted from the europium while the yttrium collects energy from the electron gun and passes it to the phosphor.Daane 1968, p. 818 Yttrium compounds can serve as host lattices for doping with different lanthanide cations. terbium 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 is used as a sintering additive in the production of porous silicon nitride.{{Ref patent |country=US |number=5935888 |status=patent |title= Porous silicon nitride with rodlike grains oriented |gdate=1999-08-10 |assign1=Agency Ind Science Techn (JP)| assign2=Fine Ceramics Research Ass (JP)}}

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.{{cite journal|last = Carley|first = Larry|url = http://www.babcox.com/editorial/cm/cm120032.htm

|title = Spark Plugs: What's Next After Platinum?|date=December 2000

|journal = Counterman|access-date = 2008-09-07 |archive-url = https://web.archive.org/web/20080501064053/http://www.babcox.com/editorial/cm/cm120032.htm |archive-date = 2008-05-01}} Yttrium is used in gas mantles for propane lanterns as a replacement for thorium, which is radioactive.{{Ref patent|country=US| number=4533317|status=patent| gdate=1985-08-06| title = Yttrium oxide mantles for fuel-burning lanterns|invent1=Addison, Gilbert J. |assign1= The Coleman Company, Inc.}}

File:Yag-rod.jpg

Yttrium is used in the production of a large variety of synthetic garnets,{{cite journal|url = http://www.minsocam.org/ammin/AM36/AM36_133.pdf|title = The role of yttrium and other minor elements in the garnet group|last = Jaffe|first = H. W.|journal = American Mineralogist|date = 1951|access-date = 2008-08-26|pages = 133–155}} and yttria is used to make yttrium iron garnets ({{chem|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.{{cite journal|title=The full magnon spectrum of yttrium iron garnet |first1=Andrew J.|last1=Princep|first2=Russell A.|last2=Ewings|first3=Andrew T.|last3=Boothroyd|date=14 November 2017|journal=Quantum Materials|volume=2 |issue=1 |pages=63 |bibcode=2017npjQM...2...63P |arxiv=1705.06594 |doi=10.1038/s41535-017-0067-y |s2cid=66404203}} Yttrium, iron, aluminium, and gadolinium garnets (e.g. {{chem2|Y3(Fe,Al)5O12}} and {{chem2|Y3(Fe,Gd)5O12}}) have important magnetic properties. YIG is also very efficient as an acoustic energy transmitter and transducer.{{cite journal|doi= 10.1016/j.jallcom.2006.05.023|title = Preparation and characterization of yttrium iron garnet (YIG) nanocrystalline powders by auto-combustion of nitrate-citrate gel

|date= 2007|last1= Vajargah|first1 = S. Hosseini|journal= Journal of Alloys and Compounds

|volume= 430|issue =1–2|pages= 339–343|last2= Madaahhosseini|first2= H.|last3= Nemati|first3= Z.}} Yttrium aluminium garnet ({{chem|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.{{Ref patent |country=US |number=6409938 |status=patent |title=Aluminum fluoride flux synthesis method for producing cerium doped YAG|gdate=2002-06-25 |invent1=Comanzo Holly Ann|assign1=General Electrics}}{{cite book|publisher = Gemological Institute of America|title = GIA Gem Reference Guide|date = 1995|isbn = 978-0-87311-019-8}}{{Cite journal | doi = 10.1109/PROC.1966.5112| title = Crystalline solid lasers| journal = Proceedings of the IEEE| volume = 54| issue = 10| pages = 1474–86| year = 1966| last1 = Kiss | first1 = Z. J. | last2 = Pressley | first2 = R. J. | pmid = 20057583}}

YAG, yttria, yttrium lithium fluoride (LiYF{{sub|4}}), and yttrium orthovanadate (YVO{{sub|4}}) are used in combination with dopants such as neodymium, erbium, ytterbium in near-infrared lasers.{{cite journal|first = J.|last = Kong|author2=Tang, D. Y. |author3=Zhao, B. |author4=Lu, J. |author5=Ueda, K. |author6= Yagi, H. |author7= Yanagitani, T. |name-list-style= amp |title = 9.2-W diode-pumped Yb:Y{{sub|2}}O{{sub|3}} ceramic laser|journal = Applied Physics Letters|volume = 86|date = 2005|doi = 10.1063/1.1914958|pages = 116|issue = 16|bibcode=2005ApPhL..86p1116K|doi-access = free}}{{cite journal|first = M.|last = Tokurakawa|author2=Takaichi, K. |author3=Shirakawa, A. |author4=Ueda, K. |author5=Yagi, H. |author6= Yanagitani, T. |author7= Kaminskii, A. A. |name-list-style= amp |title = Diode-pumped 188 fs mode-locked Yb{{sup|3+}}:Y{{sub|2}}O{{sub|3}} ceramic laser|journal = Applied Physics Letters|volume = 90|pages = 071101| date = 2007|doi=10.1063/1.2476385|issue = 7|bibcode=2007ApPhL..90g1101T}} 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 the Czochralski process.{{cite journal|journal = Journal of the Serbian Chemical Society |date = 2002|volume = 67|issue = 4|pages = 91–300|doi = 10.2298/JSC0204291G|title = The growth of Nd: YAG single crystals|author = Golubović, Aleksandar V.|author2 = Nikolić, Slobodanka N.|author3 = Gajić, Radoš|author4 = Đurić, Stevan|author5 = Valčić, Andreja|doi-access = free}}

Small amounts of yttrium (0.1 to 0.2%) have been used to reduce the grain sizes of chromium, molybdenum, titanium, and zirconium.{{cite book|chapter=Yttrium|title =Periodic Table of Elements: LANL |chapter-url = http://periodic.lanl.gov/39.shtml|publisher = Los Alamos National Security}} 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 the cubic form of zirconia in jewelry.{{cite web|url = http://www.emporia.edu/earthsci/amber/go340/students/berg/cz.html|title = Cubic Zirconia|access-date = 2008-08-26|first = Jessica|last = Berg|publisher = Emporia State University|archive-url = https://web.archive.org/web/20080924074309/http://www.emporia.edu/earthsci/amber/go340/students/berg/cz.html|archive-date = 2008-09-24|url-status = dead}}

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 ({{sup|90}}Y) 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.Emsley 2001, p. 495 It works by adhering to monoclonal antibodies, which in turn bind to cancer cells and kill them via intense β-radiation from the {{sup|90}}Y (see monoclonal antibody therapy).{{cite journal|journal = Cancer Research|volume =64|pages = 6200–6206|date =2004|title = A Single Treatment of Yttrium-90-labeled CHX-A{{'}}'–C6.5 Diabody Inhibits the Growth of Established Human Tumor Xenografts in Immunodeficient Mice|author1 = Adams, Gregory P.|doi = 10.1158/0008-5472.CAN-03-2382|pmid = 15342405|issue = 17|author2 =Shaller, C. C.|author3 =Dadachova, E.|author4 =Simmons, H. H.|author5 =Horak, E. M.|author6 =Tesfaye, A.|author7 =Klein-Szanto A. J.|author8 =Marks, J. D.|author9 =Brechbiel, M. W.|author10 =Weiner, L. M.|s2cid =34205736|display-authors=1}}

A technique called radioembolization 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 {{sup|90}}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 the entire liver, but works on one segment or one lobe at a time and may require multiple procedures.{{cite journal |title=Chemoembolization and Radioembolization for Hepatocellular Carcinoma |journal=Clinical Gastroenterology and Hepatology |volume=11 |issue=6 |date=2013 |pages=604–611 |pmid=23357493|pmc=3800021|last1=Salem |first1=R |last2=Lewandowski |first2=R. J |doi=10.1016/j.cgh.2012.12.039 }}

Also see radioembolization in the case of combined cirrhosis and hepatocellular carcinoma.

Needles made of {{sup|90}}Y, which can cut more precisely than scalpels, have been used to sever pain-transmitting nerves in the spinal cord, and {{sup|90}}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.{{cite journal|first = M.|last = Fischer|author2=Modder, G. |title = Radionuclide therapy of inflammatory joint diseases|journal = Nuclear Medicine Communications|volume = 23

|issue = 9|pages = 829–831|date = 2002|doi = 10.1097/00006231-200209000-00003|pmid = 12195084}}

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,{{cite journal|title = Laser robotically assisted nerve-sparing radical prostatectomy: a pilot study of technical feasibility in the canine model|journal = BJU International|volume = 102

|issue = 5|date = 2008|pmid = 18694410

|doi = 10.1111/j.1464-410X.2008.07708.x|last1 = Gianduzzo|first1 = Troy|last2 = Colombo|first2 = Jose R. Jr.|last3 = Haber|first3 = Georges-Pascal|last4 = Hafron|first4 = Jason|last5 = Magi-Galluzzi|first5 = Cristina|last6 = Aron|first6 = Monish|last7 = Gill|first7 = Inderbir S.|last8 = Kaouk|first8 = Jihad H.|pages = 598–602|s2cid = 10024230}} and erbium-doped lasers are coming into use for cosmetic skin resurfacing.

{{main | high-temperature superconductor }}

File:YBCO-modified.jpg superconductor]]

Yttrium is a key ingredient in the yttrium barium copper oxide (YBa{{sub|2}}Cu{{sub|3}}O{{sub|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 the liquid helium required for metallic superconductors, the operating costs for applications would be less.

The actual superconducting material is often written as YBa₂Cu₃O_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 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 is still a mystery. What is known is that the composition of the copper-oxide materials must be precisely controlled for superconductivity to occur.{{cite web|url=http://www.ch.ic.ac.uk/rzepa/mim/century/html/ybco_text.htm |publisher=Imperial College|access-date=2009-12-20|title=Yttrium Barium Copper Oxide – YBCO}}

This superconductor is a black and green, multi-crystal, multi-phase mineral. Researchers are studying a class of materials known as perovskites that are alternative combinations of these elements, hoping to develop a practical high-temperature superconductor.

{{Clear}}

Yttrium is used in small quantities in the cathodes of some Lithium iron phosphate battery (LFP), which are then commonly called LiFeYPO{{sub|4}} chemistry, or LYP. Similar to LFP, LYP batteries offer high energy density, good safety and long life. But LYP offers higher cathode stability, and prolongs the life of the battery, by protecting the physical structure of the cathode, especially at higher temperatures and higher charging / discharge current. LYP batteries find use in stationary applications (off-grid solar systems), electric vehicles (some cars), as well other applications (submarines, ships), similar to LFP batteries, but often at improved safety and cycle life time. LYP cells have essentially the same nominal voltage as LFP, 3.25{{nbsp}}V, but the maximum charging voltage is 4.0{{nbsp}}V,{{Cite web|title=40Ah Thunder Sky Winston LiFePO4 Battery WB-LYP40AHA|url=https://www.evlithium.com/thunder-sky-winston-battery/lifepo4-40ah.html|access-date=2021-05-26|website=www.evlithium.com}} and the charging and discharge characteristics are very similar.{{cite web|access-date=2019-07-21|title=Lithium Yttrium Iron Phosphate Battery|url=https://medium.com/@balqon/lithium-yttrium-iron-phosphate-battery-abe28c943498|date=2013-08-22}}

In 2009, Professor Mas Subramanian and associates at Oregon State University discovered that yttrium can be combined with indium and manganese to form an intensely blue, non-toxic, inert, fade-resistant pigment, YInMn blue, the first new blue pigment discovered in 200 years.

Yttrium can be highly toxic to humans, animals and plants.

Water-soluble compounds of yttrium are considered mildly toxic, while its insoluble compounds are non-toxic. In experiments on animals, yttrium and its compounds caused lung and liver damage, though toxicity varies with different yttrium compounds. In rats, inhalation of yttrium citrate caused pulmonary edema and dyspnea, while inhalation of yttrium chloride caused liver edema, pleural effusions, and pulmonary hyperemia.{{cite web|url=https://www.osha.gov/SLTC/healthguidelines/yttriumandcompounds/recognition.html |title=Occupational Safety and Health Guideline for Yttrium and Compounds |access-date=2008-08-03 |publisher=United States Occupational Safety and Health Administration |date=2007-01-11 |url-status=dead |archive-url=https://web.archive.org/web/20130302060936/https://www.osha.gov/SLTC/healthguidelines/yttriumandcompounds/recognition.html |archive-date=March 2, 2013 }} (public domain text)

Exposure to yttrium compounds in humans may cause lung disease. Workers exposed to airborne yttrium europium vanadate dust experienced mild eye, skin, and upper respiratory tract irritation—though this may be caused by the vanadium content rather than the yttrium. Acute exposure to yttrium compounds can cause shortness of breath, coughing, chest pain, and cyanosis. The Occupational Safety and Health Administration (OSHA) limits exposure to yttrium in the workplace to {{cvt|1|mg/m3|oz/in3|lk=out}} over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) is {{cvt|1|mg/m3|oz/in3}} over an 8-hour workday. At levels of {{cvt|500|mg/m3|oz/in3}}, yttrium is immediately dangerous to life and health.{{Cite web|title = CDC – NIOSH Pocket Guide to Chemical Hazards – Yttrium|url = https://www.cdc.gov/niosh/npg/npgd0673.html|website = www.cdc.gov|access-date = 2015-11-27}} Yttrium dust is highly flammable.

• {{portal-inline|Chemistry|left=yes}}

{{notelist}}

{{Reflist|30em}}

{{refbegin}}

• {{cite book

|last = Daane

|first = A. H.

|title = The Encyclopedia of the Chemical Elements

|chapter-url = https://archive.org/details/encyclopediaofch00hamp

|chapter-url-access = registration

|publisher = Reinhold Book Corporation

|location = New York

|date = 1968

|editor = Hampel, Clifford A.

|chapter = Yttrium

|pages = [https://archive.org/details/encyclopediaofch00hamp/page/810 810–821]

|lccn = 68029938

|oclc = 449569

|ref = Daane1968}}

• {{cite book

|title = Nature's Building Blocks: An A–Z Guide to the Elements

|last = Emsley

|first = John

|author-link = John Emsley

|publisher = Oxford University Press

|date = 2001

|location = Oxford, England, UK

|isbn = 978-0-19-850340-8

|chapter = Yttrium

|pages = [https://archive.org/details/naturesbuildingb0000emsl/page/495 495–498]

|ref = Emsley2001

|chapter-url = https://archive.org/details/naturesbuildingb0000emsl/page/495

}}

• {{cite journal

|first= Johan

|last = Gadolin

|author-link = Johan Gadolin

|title = Undersökning af en svart tung Stenart ifrån Ytterby Stenbrott i Roslagen

|journal = Kongl. Vetenskaps Academiens Nya Handlingar

|volume = 15

|date= 1794

|pages= 137–155

|ref = Gadolin1794

}}

• {{cite book

|last = Greenwood

|first = N. N.

|author2=Earnshaw, A.

|title = Chemistry of the Elements

|edition = 2nd

|publisher = Butterworth-Heinemann

|location = Oxford

|year = 1997

|isbn = 978-0-7506-3365-9

|ref = CITEREFGreenwood1997

}}

• {{cite book|ref=Gupta |chapter=Ch. 1.7.10 Phosphors |chapter-url=https://vector.umd.edu/images/links/Extractive_Metallurgy_of_Rare_Earths_Gupta.pdf|title=Extractive metallurgy of rare earths |last1=Gupta |first1=C. K. |last2=Krishnamurthy |first2=N. |publisher=CRC Press |date=2005 |isbn=978-0-415-33340-5 |url-status=live |archive-url=https://web.archive.org/web/20120623013009/http://vector.umd.edu/links_files/Extractive%20Metallurgy%20of%20Rare%20Earths%20%28Gupta%29.pdf |archive-date=2012-06-23 }}
• {{cite book

|title = Guide to the Elements

|chapter-url = https://archive.org/details/guidetoelements00stwe

|chapter-url-access = registration

|edition = Revised

|first = Albert

|last = Stwertka

|publisher = Oxford University Press

|date = 1998

|chapter = Yttrium

|pages = [https://archive.org/details/guidetoelements00stwe/page/115 115–116]

|isbn = 978-0-19-508083-4

|ref = Stwertka1998

}}

• {{cite web

|last = van der Krogt

|first = Peter

|title = 39 Yttrium

|url = http://elements.vanderkrogt.net/element.php?sym=Y

|date = 2005-05-05

|access-date = 2008-08-06

|work = Elementymology & Elements Multidict

|ref = Krogt

}}

{{refend}}

{{Library resources box|onlinebooks=yes}}

{{refbegin}}

• {{Ref patent |country=US |number=5734166 |status=patent |title=Low-energy neutron detector based upon lithium lanthanide borate scintillators| gdate=1998-03-31 |invent1=Czirr John B. |assign1=Mission Support Inc.}}
• {{cite web|url = http://www.epa.gov/rpdweb00/radionuclides/strontium.html#healtheffects |title = Strontium: Health Effects of Strontium-90|access-date = 2008-08-26 |publisher = US Environmental Protection Agency|date = 2008-07-31}}

{{refend}}

{{Spoken Wikipedia|Yttrium spoken.ogg|date=2011-07-12}}

• [http://pubsapp.acs.org/cen/80th/yttrium.html Yttrium by Paul C.W. Chu at acs.org]
• [http://www.periodicvideos.com/videos/039.htm Yttrium] at The Periodic Table of Videos (University of Nottingham)
• {{Cite EB1911|wstitle=Yttrium|short=x}}
• [https://link.springer.com/referenceworkentry/10.1007%2F978-3-319-39193-9_145-1 Encyclopedia of Geochemistry - Yttrium]

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Category:Chemical elements

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