Editing Holmium (section)

==Applications==

[[File:HoOxideSolution.jpg|thumb|A solution of 4% holmium oxide in 10% perchloric acid, permanently fused into a quartz [[cuvette]] as an optical calibration standard]]
Glass containing holmium oxide and holmium oxide solutions (usually in [[perchloric acid]]) have sharp optical [[Absorption (electromagnetic radiation)|absorption]] peaks in the spectral range 200 to 900&nbsp;nm. They are therefore used as a calibration standard for [[Monochromator|optical spectrophotometers]].<ref name="Allen 2007">{{cite journal | last=Allen | first=David W. | title=Holmium oxide glass wavelength standards | journal=Journal of Research of the National Institute of Standards and Technology | volume=112 | issue=6 | year=2007 | pages=303–306 | issn=1044-677X | doi=10.6028/jres.112.024 | pmid=27110474 | pmc=4655923 }}</ref><ref name="Travis 2002">{{cite journal | last1=Travis | first1=John C. | last2=Zwinkels | first2=Joanne C. | last3=Mercader | first3=Flora | display-authors=etal | title=An International Evaluation of Holmium Oxide Solution Reference Materials for Wavelength Calibration in Molecular Absorption Spectrophotometry | journal=Analytical Chemistry | volume=74 | issue=14 | date=2002-06-05 | issn=0003-2700 | doi=10.1021/ac0255680 | pages=3408–3415| pmid=12139047 }}</ref><ref>{{cite journal|url=http://www.clinchem.org/cgi/reprint/10/12/1117.pdf| journal =Clinical Chemistry| volume = 10| date =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 |url-access=subscription}}</ref> The radioactive but long-lived <sup>166m1</sup>Ho is used in calibration of [[gamma-ray spectrometer]]s.<ref>{{cite journal|title = The absolute counting of <sup>166m</sup>Ho, <sup>58</sup>Co and <sup>88</sup>Y|author = Ming-Chen Yuan|author2 = Jeng-Hung Lee|author3 = Wen-Song Hwang|name-list-style = amp|doi = 10.1016/S0969-8043(01)00226-3 |pmid = 11839051|journal = Applied Radiation and Isotopes
|volume = 56|issue = 1–2|pages = 429–434|date = 2002| bibcode=2002AppRI..56..429Y }}</ref>

Holmium is used to create the strongest artificially generated [[magnetic field]]s, when placed within high-strength magnets as a magnetic pole piece (also called a magnetic flux concentrator).<ref>{{cite journal| journal =IEEE Transactions on Magnetics| volume = 21| date =1985| display-authors = 6| author = R. W. Hoard| title =Field enhancement of a 12.5-T magnet using holmium poles| author2 = S. C. Mance| author3 = R. L. Leber| author4 = E. N. Dalder| author5 = M. R. Chaplin| author6 = K. Blair| author7 = D. H. Nelson| author8 = D. A. Van Dyke| issue=2|pages=448–450| doi=10.1109/tmag.1985.1063692|bibcode = 1985ITM....21..448H | s2cid = 121828376| url = https://digital.library.unt.edu/ark:/67531/metadc1200738/}}</ref> Holmium is also used in the manufacture of some [[permanent magnet]]s.

Holmium can act as a sensitizer in sodium yttrium fluoride which takes advantage of its absorption in the [[Near-infrared spectroscopy|NIR-II]] window. Holmium allows for lanthanide nanomaterials to have tunable emission and excitation in the NIR-II. Under 1143 nm excitation the interfacial energy transfer to other lanthanides allows a redshift in emission for biological applications.<ref>{{Cite journal |last=Wang |first=Xusheng |last2=Wu |first2=Wenxiao |last3=Yun |first3=Baofeng |last4=Huang |first4=Liwen |last5=Chen |first5=Zi-Han |last6=Ming |first6=Jiang |last7=Zhai |first7=Fuheng |last8=Zhang |first8=Hongxin |last9=Zhang |first9=Fan |date=2025-01-15 |title=An Emerging Toolkit of Ho3+ Sensitized Lanthanide Nanocrystals with NIR-II Excitation and Emission for in Vivo Bioimaging |url=https://pubs.acs.org/doi/10.1021/jacs.4c16451 |journal=Journal of the American Chemical Society |volume=147 |issue=2 |pages=2182–2192 |doi=10.1021/jacs.4c16451 |issn=0002-7863}}</ref> This allows deeper penetration than typically used 980 nm and 808 nm lasers.

Holmium-doped [[yttrium iron garnet]] (YIG) and [[yttrium lithium fluoride]] have applications in [[solid-state laser]]s, and Ho-YIG has applications in [[optical isolator]]s and in [[microwave]] equipment (e.g., [[YIG sphere]]s). Holmium lasers emit at 2.1 micrometres.<ref>{{cite journal| title=The holmium laser in urology| journal=Journal of Clinical Laser Medicine & Surgery | pmid=9728125 | volume=16 | issue=1 | date=Feb 1998| pages=13–20| last1=Wollin | first1=T. A. | last2=Denstedt | first2=J. D. | doi=10.1089/clm.1998.16.13 }}</ref> They are used in medical, dental, and [[optical fiber|fiber-optical]] applications.<ref name="appl">{{cite book| page = 30| url = https://books.google.com/books?id=F0Bte_XhzoAC&pg=PA32| title = Extractive metallurgy of rare earths| author = C. K. Gupta| author2 = Nagaiyar Krishnamurthy| publisher =CRC Press| date = 2004| isbn =0-415-33340-7}}</ref> It is also being considered for usage in the [[enucleation (surgery)|enucleation]] of the [[prostate]].<ref>{{Cite journal |last1=Gilling |first1=Peter J. |last2=Aho |first2=Tevita F. |last3=Frampton |first3=Christopher M. |last4=King |first4=Colleen J. |last5=Fraundorfer |first5=Mark R. |date=2008-04-01 |title=Holmium Laser Enucleation of the Prostate: Results at 6 Years |url=https://www.sciencedirect.com/science/article/pii/S0302283807005933 |journal=European Urology |language=en |volume=53 |issue=4 |pages=744–749 |doi=10.1016/j.eururo.2007.04.052 |pmid=17475395 |issn=0302-2838 |url-access=subscription}}</ref>

Since holmium can absorb [[nuclear fission]]-bred neutrons, it is used as a [[burnable poison]] to regulate nuclear reactors.<ref name="emsley225" /> It is used as a [[Colourant|colorant]] for [[cubic zirconia]], providing pink coloring,<ref>{{Cite journal|last=Nassau|first=Kurt|date=Spring 1981|title=Cubic zirconia: An Update.|journal=Gems & Gemology|volume=1|issue=1 |pages=9–19|doi=10.5741/GEMS.17.1.9|bibcode=1981GemG...17....9N |url=https://www.gia.edu/doc/Cubic-Zirconia.pdf}}</ref> and for [[glass]], providing yellow-orange coloring.<ref>{{Cite journal |last1=El-Batal |first1=Hatem A. |last2=Azooz |first2=Moenis A. |last3=Ezz-El-Din |first3=Fathy M. |last4=El-Alaily |first4=Nagia A. |date=2004-12-20 |title=Interaction of Gamma Rays with Calcium Aluminoborate Glasses Containing Holmium or Erbium |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1151-2916.2001.tb00959.x |journal=Journal of the American Ceramic Society |language=en |volume=84 |issue=9 |pages=2065–2072 |doi=10.1111/j.1151-2916.2001.tb00959.x |url-access=subscription}}</ref> In March 2017, [[IBM]] announced that they had developed a technique to store one [[bit]] of data on a single holmium atom set on a bed of [[magnesium oxide]].<ref>{{cite web|url=https://techcrunch.com/2017/03/08/storing-data-in-a-single-atom-proved-possible-by-ibm-researchers/|access-date=2017-03-10|title=Storing data in a single atom proved possible by IBM researchers|website=[[TechCrunch]]|last1=Coldeway|first1=Devin|date=March 9, 2017}}</ref> With sufficient quantum and classical control techniques, holmium may be a good candidate to make [[quantum computers]].<ref>{{Cite journal|last1=Forrester|first1=Patrick Robert|last2=Patthey|first2=François|last3=Fernandes|first3=Edgar|last4=Sblendorio|first4=Dante Phillipe|last5=Brune|first5=Harald|last6=Natterer|first6=Fabian Donat|date=2019-11-19|title=Quantum state manipulation of single atom magnets using the hyperfine interaction|journal=Physical Review B|language=en|volume=100|issue=18|pages=180405|doi=10.1103/PhysRevB.100.180405| arxiv=1903.00242 |issn=2469-9950|bibcode=2019PhRvB.100r0405F|doi-access=free}}</ref>

Holmium is used in the medical field, particularly in [[laser surgery]] for procedures such as kidney stone removal and prostate treatment, due to its precision and minimal tissue damage.<ref>{{cite web |url=https://www.stanfordmaterials.com/blog/holmium-properties-and-applications.html |title=Holmium: Properties and Applications |last=Loewen |first=Eric |website=Stanford Advanced Materials |access-date=Oct 23, 2024}}</ref><ref>{{cite journal |last1=Younis |first1=Zaid |last2=Ayyed |first2=Atheer |title=Influence of stone location on rate of stone clearance and complication for holmium laser lithotripsy |journal=International Journal of Urology Research |volume=6 |issue=1 |year=2024 |pages=84–90 |doi=10.33545/26646617.2024.v6.i1b.38}}</ref> Its [[isotope]], holmium-166, is applied in targeted cancer therapies, especially for liver cancer,<ref>{{cite journal |last1=Kuhnel |first1=Christian |last2=Kohler |first2=Alexander |year=2024 |title=Clinical Results of Holmium-166 Radioembolization with Personalized Dosimetry for the Treatment of Hepatocellular Carcinoma |journal=J. Pers. Med. |volume=14 |issue=7 |page=747 |doi=10.3390/jpm14070747|doi-access=free |pmid=39064001 |pmc=11278198 }}</ref> and it also enhances [[MRI]] imaging as a contrast agent.<ref>{{cite journal |last1=Maat |first1=Gerrit |last2=Seevinck |first2=Peter |year=2013 |title=MRI-based biodistribution assessment of holmium-166 poly(L-lactic acid) microspheres after radioembolisation |journal=European Radiology |volume=23 |issue=3 |pages=827–835 |doi=10.1007/s00330-012-2648-2 |doi-access=free|pmid=23014797 |pmc=3563959 }}</ref>