Editing Holmium (section)

=== Oxides and chalcogenides ===

[[Image:Holmium(III) oxide.jpg|thumb|right|[[holmium(III) oxide|Ho<sub>2</sub>O<sub>3</sub>]], left: natural light, right: under a [[cold-cathode]] fluorescent lamp]]

Holmium(III) oxide is the only oxide of holmium. It changes its color depending on the lighting conditions. In daylight, it has a yellowish color. Under [[trichromacy|trichromatic light]], it appears orange red, almost indistinguishable from the appearance of erbium oxide under the same lighting conditions.<ref>{{Cite book |last1=Ganjali |first1=Mohammad Reza |title=Lanthanides Series Determination by Various Analytical Methods |last2=Gupta |first2=Vinod Kumar |last3=Faridbod |first3=Farnoush |last4=Norouzi |first4=Parviz |date=2016-02-25 |page=27}}</ref> The color change is related to the sharp [[Spectral line|emission lines]] of trivalent holmium ions acting as red phosphors.<ref name="Su 2008">{{cite journal| doi=10.1246/cl.2008.762| title=Hydrothermal Synthesis of GdVO<sub>4</sub>:Ho<sup>3+</sup> Nanorods with a Novel White-light Emission| date=2008| last1=Su| first1=Yiguo| journal=Chemistry Letters| volume=37| pages=762–763| issue=7| last2=Li| first2=Guangshe| last3=Chen| first3=Xiaobo| last4=Liu| first4=Junjie| last5=Li| first5=Liping}}</ref> Holmium(III) oxide appears pink under a cold-cathode fluorescent lamp.

Other [[chalcogenide]]s are known for holmium. [[Holmium(III) sulfide]] has orange-yellow [[crystal]]s in the [[monoclinic crystal system]],<ref name="CRC" /> with the [[space group]]  ''P''2<sub>1</sub>/''m'' (No. 11).<ref>{{Cite book |chapter-url=https://link.springer.com/chapter/10.1007%2F10681735_623 |chapter=Ho<sub>2</sub>S<sub>3</sub>: crystal structure, physical properties |access-date=2021-06-22 |archive-date=2018-09-01 |archive-url=https://web.archive.org/web/20180901182621/https://link.springer.com/chapter/10.1007/10681735_623 |url-status=live|doi=10.1007/10681735_623|title=Non-Tetrahedrally Bonded Binary Compounds II |series=Landolt-Börnstein - Group III Condensed Matter |year=2000 |volume=41D |pages=1–3 |publisher=Springer |isbn=3-540-64966-2 }}</ref> Under high pressure, holmium(III) sulfide can form in the [[cubic crystal system|cubic]] and [[orthorhombic crystal system|orthorhombic]] [[crystal system]]s.<ref name="E. Yu Tonkov">{{cite book|first1=E. Yu |last1=Tonkov|title=Compounds and Alloys Under High Pressure A Handbook|year=1998|page=272}}</ref> It can be obtained by the reaction of holmium(III) oxide and [[hydrogen sulfide]] at {{convert|1598|K|C F}}.<ref name="Meyer">{{cite book|editor1=G. Meyer|editor2= Lester R. Morss|title=Synthesis of Lanthanide and Actinide Compounds|year=1991|page=329}}</ref> Holmium(III) selenide is also known. It is antiferromagnetic below 6&nbsp;K.<ref>{{Cite journal |last1=Bespyatov |first1=M. A. |last2=Musikhin |first2=A. E. |last3=Naumov |first3=V. N. |last4=Zelenina |first4=L. N. |last5=Chusova |first5=T. P. |last6=Nikolaev |first6=R. E. |last7=Naumov |first7=N. G. |date=2018-03-01 |title=Low-temperature thermodynamic properties of holmium selenide (2:3) |url=https://www.sciencedirect.com/science/article/pii/S0021961417303804 |journal=The Journal of Chemical Thermodynamics |language=en |volume=118 |pages=21–25 |doi=10.1016/j.jct.2017.10.013 |bibcode=2018JChTh.118...21B |issn=0021-9614 |url-access=subscription}}</ref>