Holmium(III) oxide: Difference between revisions

| RefractIndex = 1.8 <ref name=optics>{{cite journal|doi=10.1016/S0040-6090(01)01760-6|title=Preparation and optical properties of holmium oxide thin films|year=2002|author=Wiktorczyk, T|journal=Thin Solid Films|volume=405|issue=1–2|pages=238238–242|bibcode=2002TSF...405..238W}}</ref>

| SPhrasesGHSPictograms = {{S22GHS07}}, {{S24/25GHS09}}

'''Holmium(III) oxide''', or '''holmium oxide''' is a [[chemical compound]] of athe [[rare-earth element]] [[holmium]] and [[oxygen]] with the [[chemical formula|formula]] Ho₂O₃. Together with [[dysprosium(III) oxide]] (Dy₂O₃), holmium oxide is one of the most powerfully [[Paramagnetism|paramagnetic]] substances known. The oxide, also called '''holmia''', occurs as a component of the related erbium oxide [[mineral]] called [[erbia]]. Typically, the oxides of the trivalent [[lanthanide]]s coexist in nature, and separation of these components requires specialized methods. Holmium oxide is used in making specialty colored [[glass]]es. Glass containing holmium oxide and holmium oxide solutions have a series of sharp [[optical absorption]] peaks in the visible [[spectrum|spectral range]]. They are therefore traditionally used as a convenient calibration standard for [[Monochromator|optical spectrophotometers]].

Holmium oxide has a [[cubic crystal system|cubic]], yet rather complex [[bixbyite]] structure, with many atoms per unit cell and a large lattice constant of 1.06&nbsp;nm. This structure is characteristic of oxides of heavy rare-earth elements, such as Tb₂O₃, Dy₂O₃, Er₂O₃, Tm₂O₃, Yb₂O₃ and Lu₂O₃. The thermal expansion coefficient of Ho₂O₃ is also relatively large at 7.4&nbsp;×10^-6−6/°C.<ref>{{cite journal |doi =10.10161021/0022-5088(69)90137-4cr940055h|title =PreciseThe determinationBinary ofRare the lattice parameters of holmium and erbium sesquioxides atEarth elevatedOxides temperatures|year=1998 |last1=1969Adachi |authorfirst1=Gin-ya |last2=Singh,Imanaka H|journalfirst2=Nobuhito |journal=Journal ofChemical theReviews Less Common Metals|volume=98 |issue=184 |pages =172|last21479–1514 =Dayal|first2 pmid=B|issue11848940 =2}}</ref>

| volume = 89|pages = 521|year = 1879|url = httphttps://gallica.bnf.fr/ark:/12148/bpt6k3046j/f550.table}}

| title = Sur deux nouveaux éléments dans l'erbine|author = [[Per Teodor Cleve]]|author-link = Per Teodor Cleve| journal = Comptes rendus de l'Académie des sciences|volume = 89|pages = 478

Using the method developed by [[Carl Gustaf Mosander]], Cleve first removed all of the known contaminants from erbia. The result of that effort was two new materials, one brown and one green. He named the brown substance holmia (after the Latin name for Cleve's home town, Stockholm) and the green one thulia. Holmia was later found to be the holmium oxide and thulia was [[Thulium(III) oxide|thulium oxide]].<ref name=history>{{cite book| pages=180–181| url =httphttps://books.google.com/books?id=Yhi5X7OwuGkC&pg=PA180| title =Nature's building blocks: an A-Z guide to the elements| author =John Emsley| publisher=Oxford University Press |location =US| year = 2001| isbn = 0-19-850341-5}}</ref>

A typical extraction process of holmium oxide can be simplified as follows: Thethe mineral mixtures are crushed and ground. Monazite, because of its magnetic properties can be separated by repeated electromagnetic separation. After separation, it is treated with hot concentrated [[sulfuric acid]] to produce water-soluble sulfates of several rare earth elements. The acidic filtrates are partially neutralized with [[sodium hydroxide]] to pH 3-43–4. [[Thorium]] precipitates out of solution as hydroxide and is removed. After that, the solution is treated with [[ammonium oxalate]] to convert rare earths in to their insoluble [[oxalate]]s. The oxalates are converted to oxides by annealing. The oxides are dissolved in [[nitric acid]] that excludes one of the main components, [[cerium]], whose oxide is insoluble in HNO₃.

The most efficient separation routine for holmium oxide from the rare-earths is [[ion exchange]]. In this process, rare-earth ions are adsorbed onto suitable ion-exchange resin by exchange with hydrogen, ammonium or cupric ions present in the resin. The rare earth ions are then selectively washed out by suitable complexing agent, such as ammonium citrate or nitrilotracetatenitrilotriacetate.<ref name=patnaik>{{cite book|last =Patnaik|first =Pradyot|year = 2003|title =Handbook of Inorganic Chemical Compounds|publisher = McGraw-Hill|pages = 340;445| isbn =0-07-049439-8|url= httphttps://books.google.com/books?id=Xqj-TTzkvTEC&pg=PA445|accessdateaccess-date = 2009-06-06}}</ref>

Holmium oxide is one of the colorants used for [[cubic zirconia]] and [[glass]], providing yellow or red coloring.<ref>{{cite web| accessdateaccess-date=2009-06-06| url=http://www.geologyrocks.co.uk/tutorials/cubic_zirconia| title=Cubic zirconia| archive-url=https://web.archive.org/web/20090424075328/http://www.geologyrocks.co.uk/tutorials/cubic_zirconia| archive-date=2009-04-24| url-status=dead}}</ref> Glass containing holmium oxide and holmium oxide solutions (usually in [[perchloric acid]]) have sharp optical absorption peaks in the spectral range 200-900&nbsp;nm. They are therefore used as a calibration standard for [[Monochromator|optical spectrophotometers]]<ref>{{cite journal|url=http://www.clinchem.org/cgi/reprint/10/12/1117.pdf| journal =Clinical Chemistry| volume = 10| year =1964|title =Uses for a Holmium Oxide Filter in Spectrophotometry| author = R. P. MacDonald| pmid=14240747| issue=12|pages=1117–20| doi =10.1093/clinchem/10.12.1117}}</ref><ref>{{cite journal| doi = 10.1021/ac0255680| title = An International Evaluation of Holmium Oxide Solution Reference Materials for Wavelength Calibration in Molecular Absorption Spectrophotometry| year = 2002| author = Travis, John C.| journal = Analytical Chemistry| volume = 74| pages = 3408–15| pmid = 12139047| last2 = Zwinkels| first2 = JC| last3 = Mercader| first3 = F| last4 = Ruíz| first4 = A| last5 = Early| first5 = EA| last6 = Smith| first6 = MV| last7 = Noël| first7 = M| last8 = Maley| first8 = M| last9 = Kramer| first9 = GW| last10 = Eckerle| first10 = Kenneth L.| last11 = Duewer| first11 = David L.| issue = 14| display-authors = 8}}</ref> and are available commercially.<ref>{{cite web| url=http://www.labshoponline.com/holmium-glass-filter-spectrophotometer-calibration-p-88.html| accessdateaccess-date=2009-06-06| title =Holmium Glass Filter for Spectrophotometer Calibration| url-status=dead| archive-url=https://web.archive.org/web/20100314163906/http://www.labshoponline.com/holmium-glass-filter-spectrophotometer-calibration-p-88.html| archive-date=2010-03-14}}</ref> As most other oxides of rare-earth elements, holmium oxide is used as a specialty [[catalyst]], [[phosphor]] and a [[laser]] material. Holmium laser operates at wavelength of about 2.08 micrometres, either in pulsed or continuous regime. This laser is eye safe and is used in medicine, [[LIDARlidar]]s, wind velocity measurements and atmosphere monitoring.<ref>{{cite book| page=125| url=httphttps://books.google.com/books?id=0BFHEev-pMgC&pg=PA127| title = The physics and engineering of solid state lasers| author = Yehoshua Y. Kalisky| publisher = SPIE Press| year = 2006| isbn = 0-8194-6094-X}}</ref>

Holmium(III) oxide is, compared to many other compounds, not very dangerous, although repeated overexposure can cause [[granuloma]] and [[hemoglobinemia]]. It has low oral, dermal and inhalation toxicities and is non-irritating. The acute oral [[median lethal dose]] (LD₅₀) is greater than 1 g per kilogram of body weight.<ref>{{cite web| accessdateaccess-date=2009-06-06| url=http://www.espimetals.com/msds%27s/holmiumoxide.pdf| title= External MSDS| archive-url=https://web.archive.org/web/20080309110140/http://www.espimetals.com/msds%27s/holmiumoxide.pdf| archive-date=2008-03-09| url-status=dead}}</ref>