Editing Dysprosium (section)

==Characteristics==

===Physical properties===
[[Image:Dysprosium.jpg|thumb|upright=0.4|left|Dysprosium sample]]
Dysprosium is a [[rare-earth element]] and has a metallic, bright silver luster. It is quite soft and can be machined without sparking if overheating is avoided. Dysprosium's physical characteristics can be greatly affected by even small amounts of impurities.<ref name="CRC">{{Cite book |editor = Lide, David R. |chapter = Dysprosium |year = 2007–2008 |title = CRC Handbook of Chemistry and Physics |volume = 4 |pages = 11 |location = New York |publisher = CRC Press |isbn = 978-0-8493-0488-0}}</ref>

Dysprosium and [[holmium]] have the highest magnetic strengths of the elements,<ref name="nbb" /> especially at low temperatures.<ref name="krebs" /> Dysprosium has a simple [[ferromagnetic]] ordering at temperatures below its [[Curie temperature]] of {{convert|90.5|K|C}}, at which point it undergoes a first-order phase transition from the [[Orthorhombic crystal system|orthorhombic crystal structure]] to [[hexagonal close-packed]] (hcp).<ref name="Arblaster 2018" /><!--Citation is defined in infobox: {{cite book |last=Arblaster |first= John W. |title=Selected Values of the Crystallographic Properties of Elements |publisher=ASM International |publication-place=Materials Park, Ohio |date=2018 |isbn=978-1-62708-155-9}}--> It then has a [[Helimagnetism|helical antiferromagnetic]] state, in which all of the atomic magnetic moments in a particular [[basal plane]] layer are parallel and oriented at a fixed angle to the moments of adjacent layers. This unusual antiferromagnetism transforms into a disordered ([[paramagnetic]]) state at {{convert|179|K|C}}.<ref>{{cite journal |journal = IRM Quarterly |year = 2000 |volume = 10 |issue = 3 |page = 6 |author = Jackson, Mike |url = http://www.irm.umn.edu/quarterly/irmq10-3.pdf |title = Wherefore Gadolinium? Magnetism of the Rare Earths |access-date = 2009-05-03 |archive-url = https://web.archive.org/web/20170712151422/http://www.irm.umn.edu/quarterly/irmq10-3.pdf |archive-date = 2017-07-12 |url-status = dead}}</ref> It transforms from the hcp phase to the [[body-centered cubic]] phase at {{convert|1654|K|C}}.<ref name="Arblaster 2018" />

===Chemical properties===
Dysprosium metal retains its luster in dry air but it will tarnish slowly in moist air, and it burns readily to form [[dysprosium(III) oxide]]:
:4 Dy + 3 O<sub>2</sub> → 2 Dy<sub>2</sub>O<sub>3</sub>

Dysprosium is quite electropositive and reacts slowly with cold water (and quickly with hot water) to form [[dysprosium hydroxide]]:
:2 Dy (s) + 6 H<sub>2</sub>O (l) → 2 Dy(OH)<sub>3</sub> (aq) + 3 H<sub>2</sub> (g)

Dysprosium hydroxide decomposes to form DyO(OH) at elevated temperatures, which then decomposes again to dysprosium(III) oxide.<ref>{{cite journal|url=http://linkinghub.elsevier.com/retrieve/pii/S092583881202052X|doi=10.1016/j.jallcom.2012.11.068|pages=333–337|title=Controlled synthesis and characterization of large-scale, uniform sheet-shaped dysprosium hydroxide nanosquares by hydrothermal method|volume=553|journal=Journal of Alloys and Compounds|date=March 2013|issn=0925-8388|access-date=2018-06-13|author=Junyang Jin, Yaru Ni, Wenjuan Huang, Chunhua Lu, Zhongzi Xu}}</ref>

Dysprosium metal vigorously reacts with all the halogens at above 200&nbsp;°C:{{citation needed|date=July 2022}}
:2 Dy (s) + 3 F<sub>2</sub> (g) → 2 DyF<sub>3</sub> (s) [green]
:2 Dy (s) + 3 Cl<sub>2</sub> (g) → 2 DyCl<sub>3</sub> (s) [white]
:2 Dy (s) + 3 Br<sub>2</sub> (l) → 2 DyBr<sub>3</sub> (s) [white]
:2 Dy (s) + 3 I<sub>2</sub> (g) → 2 DyI<sub>3</sub> (s) [green]

Dysprosium dissolves readily in dilute [[sulfuric acid]] to form solutions containing the yellow Dy(III) ions, which exist as a [Dy(OH<sub>2</sub>)<sub>9</sub>]<sup>3+</sup> complex:<ref>{{cite web| url =https://www.webelements.com/dysprosium/chemistry.html| title =Chemical reactions of Dysprosium| publisher=Webelements| access-date=2012-08-16}}</ref>

:2 Dy (s) + 3 H<sub>2</sub>SO<sub>4</sub> (aq) → 2 Dy<sup>3+</sup> (aq) + 3 {{chem|SO|4|2-}} (aq) + 3 H<sub>2</sub> (g)

The resulting compound, dysprosium(III) sulfate, is noticeably paramagnetic.

===Compounds===
[[File:Dysprosium-sulfate.jpg|left|thumb|upright|Dysprosium sulfate, Dy<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>]]
{{See also|:Category:Dysprosium compounds|l1=Dysprosium compounds}}
Dysprosium halides, such as DyF<sub>3</sub> and DyBr<sub>3</sub>, tend to take on a yellow color. [[Dysprosium(III) oxide|Dysprosium oxide]], also known as dysprosia, is a white powder that is highly [[magnetic]], more so than iron oxide.<ref name="krebs" />

Dysprosium combines with various non-metals at high temperatures to form binary compounds with varying composition and oxidation states +3 and sometimes +2, such as DyN, DyP, DyH<sub>2</sub> and DyH<sub>3</sub>; DyS, DyS<sub>2</sub>, Dy<sub>2</sub>S<sub>3</sub> and Dy<sub>5</sub>S<sub>7</sub>; DyB<sub>2</sub>, DyB<sub>4</sub>, DyB<sub>6</sub> and DyB<sub>12</sub>, as well as Dy<sub>3</sub>C and Dy<sub>2</sub>C<sub>3</sub>.<ref name="patnaik" />

Dysprosium carbonate, Dy<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>, and dysprosium sulfate, Dy<sub>2</sub>(SO<sub>4</sub>)<sub>3</sub>, result from similar reactions.<ref name="heiserman" /> Most dysprosium compounds are soluble in water, though dysprosium carbonate tetrahydrate (Dy<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>·4H<sub>2</sub>O) and dysprosium oxalate decahydrate (Dy<sub>2</sub>(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>·10H<sub>2</sub>O) are both insoluble in water.<ref name="perry">{{cite book |title = Handbook of Inorganic Compounds |author=Perry, D. L. |pages = 152–154|year = 1995|isbn = 978-0-8493-8671-8|publisher = CRC Press}}</ref><ref>{{cite journal|title = Zur Kenntnis der Verbindungen des Dysprosiums|pages = 1274–1280|first1 = G.|last1 = Jantsch|doi = 10.1002/cber.19110440215|journal = Berichte der Deutschen Chemischen Gesellschaft|volume = 44|issue = 2|year = 1911|last2 = Ohl|first2 = A.|url = https://zenodo.org/record/1426439}}</ref> Two of the most abundant dysprosium carbonates, Dy<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>·2–3H<sub>2</sub>O (similar to the mineral tengerite-(Y)), and DyCO<sub>3</sub>(OH) (similar to minerals kozoite-(La) and kozoite-(Nd)), are known to form via a poorly ordered (amorphous) precursor phase with a formula of Dy<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>·4H<sub>2</sub>O. This amorphous precursor consists of highly hydrated spherical [[nanoparticle]]s of 10–20&nbsp;nm diameter that are exceptionally stable under dry treatment at ambient and high temperatures.<ref>{{cite journal|author=Vallina, B., Rodriguez-Blanco, J.D., Brown, A.P., Blanco, J.A. and Benning, L.G.|year=2013|title=Amorphous dysprosium carbonate: characterization, stability and crystallization pathways|journal=Journal of Nanoparticle Research|volume=15|issue=2|pages=1438|bibcode=2013JNR....15.1438V|citeseerx=10.1.1.705.3019|doi=10.1007/s11051-013-1438-3|s2cid=95924050}}</ref>

Dysprosium forms several [[intermetallic]]s, including the [[dysprosium stannides]].<ref>{{Cite journal |last=Okamoto |first=H. |date=2005-04-01 |title=Dy-Sn (Dysprosium-Tin) |url=http://www.ingentaselect.com/rpsv/cgi-bin/cgi?ini=xref&body=linker&reqdoi=10.1361/15477030523247 |journal=Journal of Phase Equilibria & Diffusion |language=en |volume=26 |issue=2 |pages=200–202 |doi=10.1361/15477030523247}}</ref>

===Isotopes===
{{main|Isotopes of dysprosium}}
Naturally occurring dysprosium is composed of seven [[isotope]]s: <sup>156</sup>Dy, <sup>158</sup>Dy, <sup>160</sup>Dy, <sup>161</sup>Dy, <sup>162</sup>Dy, <sup>163</sup>Dy, and <sup>164</sup>Dy. These are all considered stable, although only the last two are theoretically stable: the others can theoretically undergo alpha decay. Of the naturally occurring isotopes, <sup>164</sup>Dy is the most [[natural abundance|abundant]] at 28%, followed by <sup>162</sup>Dy at 26%. The least abundant is <sup>156</sup>Dy at 0.06%.{{NUBASE2016|ref}} Dysprosium is the heaviest element to have isotopes that are predicted to be stable rather than [[observationally stable]] isotopes that are predicted to be radioactive.

Twenty-nine [[radioisotopes]] have been synthesized, ranging in atomic mass from 138 to 173. The most stable of these is <sup>154</sup>Dy, with a [[half-life]] of approximately 3{{e|6}}&nbsp;years, followed by <sup>159</sup>Dy with a half-life of 144.4&nbsp;days. The least stable is <sup>138</sup>Dy, with a half-life of 200&nbsp;ms. As a general rule, isotopes that are lighter than the stable isotopes tend to decay primarily by β<sup>+</sup> decay, while those that are heavier tend to decay by [[Beta decay#β− decay|β<sup>−</sup> decay]]. However, <sup>154</sup>Dy decays primarily by alpha decay, and <sup>152</sup>Dy and <sup>159</sup>Dy decay primarily by [[electron capture]].{{NUBASE2016|name}} Dysprosium also has at least 11 [[metastable isomer]]s, ranging in atomic mass from 140 to 165. The most stable of these is <sup>165m</sup>Dy, which has a half-life of 1.257&nbsp;minutes. <sup>149</sup>Dy has two metastable isomers, the second of which, <sup>149m2</sup>Dy, has a half-life of 28&nbsp;ns.{{NUBASE2016|name}}