Editing Europium (section)

==History==
Although europium is present in most of the minerals containing the other rare elements, due to the difficulties in separating the elements it was not until the late 1800s that the element was isolated. [[William Crookes]] observed the phosphorescent spectra of the rare elements including those eventually assigned to europium.<ref>{{cite journal|jstor = 92772|pages = 411–414|last1 = Crookes|first1 = W.|author-link=William Crookes|title = On the Phosphorescent Spectra of S δ and Europium|volume = 76|issue = 511|journal = Proceedings of the Royal Society of London|date = 1905|bibcode = 1905RSPSA..76..411C|doi = 10.1098/rspa.1905.0043|doi-access = free}}</ref>

Europium was first found in 1892 by [[Paul Émile Lecoq de Boisbaudran]], who obtained basic fractions from samarium-gadolinium concentrates which had spectral lines not accounted for by samarium or [[gadolinium]]. However, the discovery of europium is generally credited to [[France|French]] [[chemist]] [[Eugène-Anatole Demarçay]], who suspected samples of the recently discovered element samarium were contaminated with an unknown element in 1896 and who was able to isolate it in 1901; he then named it ''europium''.<ref>{{cite journal|url = http://gallica.bnf.fr/ark:/12148/bpt6k30888/f1580.image| journal = [[Comptes rendus de l'Académie des sciences|Comptes rendus]]| first = Eugène-Anatole|last = Demarçay|title = Sur un nouvel élément l'europium|volume = 132|pages = 1484–1486|date = 1901}}</ref><ref name="XVI">{{cite journal|doi = 10.1021/ed009p1751|title = The discovery of the elements. XVI. The rare earth elements|date = 1932|last1 = Weeks|first1 = Mary Elvira|author-link1=Mary Elvira Weeks|journal = Journal of Chemical Education|volume = 9|issue = 10|pages = 1751|bibcode = 1932JChEd...9.1751W }}</ref><ref name="Weeks">{{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 }}</ref><ref name="Marshall">{{cite journal |last1=Marshall |first1=James L. |last2=Marshall |first2=Virginia R. |title=Rediscovery of the Elements: Europium-Eugene Demarçay |journal=The Hexagon |date=2003 |issue=Summer |pages=19–21 |url=http://www.chem.unt.edu/~jimm/REDISCOVERY%207-09-2018/Hexagon%20Articles/demarcay%20and%20europium.pdf |access-date=18 December 2019}}</ref><ref name="Virginia">{{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}}</ref>

When the europium-doped [[yttrium orthovanadate]] red phosphor was discovered in the early 1960s, and understood to be about to cause a revolution in the color television industry, there was a scramble for the limited supply of europium on hand among the monazite processors,<ref name="Sri1">{{cite journal | url = http://www.electrochem.org/dl/interface/sum/sum03/IF6-03-Pages48-51.pdf | journal = The Electrochemical Society Interface | date = 2003 | pages = 48–51 | title =Phosphors | first1 =A. M. | last1= Srivastava | first2 = C. R. | last2=Ronda | volume = 12 | issue = 2 | doi = 10.1149/2.F11032IF }}</ref> as the typical europium content in monazite is about 0.05%. However, the Molycorp [[bastnäsite]] deposit at the [[Mountain Pass mine|Mountain Pass rare earth mine]], [[California]], whose lanthanides had an unusually high europium content of 0.1%, was about to come on-line and provide sufficient europium to sustain the industry. Prior to europium, the color-TV red phosphor was very weak, and the other phosphor colors had to be muted, to maintain color balance. With the brilliant red europium phosphor, it was no longer necessary to mute the other colors, and a much brighter color TV picture was the result.<ref name="Sri1" /> Europium has continued to be in use in the TV industry ever since as well as in computer monitors. Californian bastnäsite now faces stiff competition from [[Bayan Obo]], China, with an even "richer" europium content of 0.2%.

[[Frank Spedding]], celebrated for his development of the ion-exchange technology that revolutionized the rare-earth industry in the mid-1950s, once related the story of how<ref>{{cite journal|doi = 10.1039/DF9490700214|title = Large-scale separation of rare-earth salts and the preparation of the pure metals|date = 1949|last1 = Spedding|first1 = Frank H.|journal = Discussions of the Faraday Society|volume = 7|pages = 214 | author-link = Frank Spedding}}</ref> he was lecturing on the rare earths in the 1930s, when an elderly gentleman approached him with an offer of a gift of several pounds of europium oxide. This was an unheard-of quantity at the time, and Spedding did not take the man seriously. However, a package duly arrived in the mail, containing several pounds of genuine europium oxide. The elderly gentleman had turned out to be [[Herbert Newby McCoy]], who had developed a famous method of europium purification involving redox chemistry.<ref name="McCoy" /><ref>{{cite journal|url = http://www.nap.edu/openbook.php?record_id=10269&page=300–326|journal = Biographical Memoirs of the National Academy of Sciences|volume = 80|first = John D.|last = Corbett|title = Frank Harold Spedding|bibcode = 1986PhT....39e.106H|date = 1986|pages = 106–107|doi = 10.1063/1.2815016|issue = 5|doi-access = free}}</ref>