Dysprosium is achemical element; it hassymbolDy andatomic number 66. It is arare-earth element in thelanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it is found in various minerals, such asxenotime. Naturally occurring dysprosium is composed of sevenisotopes, the mostabundant of which is164Dy.
Dysprosium was first identified in 1886 byPaul Émile Lecoq de Boisbaudran, but it was not isolated in pure form until the development ofion-exchange techniques in the 1950s. Dysprosium is used to produceneodymium-iron-boron (NdFeB) magnets, which are crucial for electric vehicle motors and the efficient operation of wind turbines.[9] It is used for its high thermal neutron absorption cross-section in makingcontrol rods innuclear reactors, for its highmagnetic susceptibility (χv ≈5.44×10−3) in data-storage applications, and as a component ofTerfenol-D (amagnetostrictive material). Soluble dysprosium salts are mildly toxic, while the insoluble salts are considered non-toxic.
Dysprosium is arare-earth element and has a metallic, bright silver luster. It is 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.[10]
Dysprosium andholmium have the highest magnetic strengths of the elements,[11] especially at low temperatures.[12] Dysprosium has a simpleferromagnetic ordering at temperatures below itsCurie temperature of 90.5 K (−182.7 °C), at which point it undergoes a first-order phase transition from theorthorhombic crystal structure tohexagonal close-packed (hcp).[3] It then has ahelical antiferromagnetic state, in which all of the atomic magnetic moments in a particularbasal 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 179 K (−94 °C).[13] It transforms from the hcp phase to thebody-centered cubic phase at 1,654 K (1,381 °C).[3]
Dysprosium halides, such asDyF3 andDyBr3, tend to take on a yellow color.Dysprosium oxide, also known as dysprosia, is a white powder that is highlymagnetic, more so than iron oxide.[12]
Dysprosium combines with various non-metals at high temperatures to form binary compounds with varying composition and oxidation states +3 and sometimes +2, such asDyN,DyP, DyH2 and DyH3;DyS, DyS2,Dy2S3 and Dy5S7; DyB2, DyB4, DyB6 and DyB12, as well as Dy3C and Dy2C3.[16]
Dysprosium carbonate, Dy2(CO3)3, and dysprosium sulfate, Dy2(SO4)3, result from similar reactions.[17] Most dysprosium compounds are soluble in water, though dysprosium carbonate tetrahydrate (Dy2(CO3)3·4H2O) anddysprosium oxalate decahydrate (Dy2(C2O4)3·10H2O) are both insoluble in water.[18][19] Two of the most abundant dysprosium carbonates, Dy2(CO3)3·2–3H2O (similar to the mineral tengerite-(Y)), and DyCO3(OH) (similar to minerals kozoite-(La) and kozoite-(Nd)), are known to form via a poorly ordered (amorphous) precursor phase with a formula of Dy2(CO3)3·4H2O. This amorphous precursor consists of highly hydrated sphericalnanoparticles of 10–20 nm diameter that are exceptionally stable under dry treatment at ambient and high temperatures.[20]
Naturally occurring dysprosium is composed of sevenisotopes:156Dy,158Dy,160Dy,161Dy,162Dy,163Dy, and164Dy. 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,164Dy is the mostabundant at 28%, followed by162Dy at 26%; the rarest is156Dy at 0.06%.[7] Dysprosium is the heaviest element to have isotopes that aretheoretically stable rather than onlyobservationally stable isotopes that are predicted to be radioactive.
Twenty-nineradioisotopes have been synthesized, ranging in atomic mass from 138 to 173. The most stable of these is154Dy, with ahalf-life of 1.40×106 years, followed by159Dy with a half-life of 144.4 days. As a general rule, isotopes that are lighter than the stable isotopes tend to decay primarily by β+ decay, though154Dy decays byalpha emission and152Dy and159Dy only byelectron capture, while those that are heavier tend to decay byβ− decay.[7] Dysprosium also has at least 11metastable isomers, ranging in atomic mass from 140 to 165. The most stable of these is165mDy, which has a half-life of 1.257 minutes.
In 1878,erbium ores were found to contain the oxides ofholmium andthulium. French chemistPaul Émile Lecoq de Boisbaudran, while working withholmium oxide, separateddysprosium oxide from it in Paris in 1886.[22][23] His procedure for isolating the dysprosium involved dissolving dysprosium oxide in acid, then addingammonia to precipitate the hydroxide. He was only able to isolate dysprosium from its oxide after more than 30 attempts at his procedure. On succeeding, he named the elementdysprosium from the Greekdysprositos (δυσπρόσιτος), meaning "hard to get". The element was not isolated in relatively pure form until after the development ofion exchange techniques byFrank Spedding atIowa State University in the early 1950s.[11][24]
Due to its role in permanent magnets used for wind turbines, it has been argued[by whom?] that dysprosium will be one of the main objects of geopolitical competition in a world running on renewable energy. But this perspective has been criticised for failing to recognise that most wind turbines do not use permanent magnets and for underestimating the power of economic incentives for expanded production.[25][26]
In the high-yttrium version of these, dysprosium happens to be the most abundant of the heavylanthanides, comprising up to 7–8% of the concentrate (as compared to about 65% for yttrium).[30][31] The concentration of Dy in the Earth's crust is about 5.2 mg/kg and in sea water 0.9 ng/L.[16]
Dysprosium is obtained primarily frommonazite sand, a mixture of variousphosphates. The metal is obtained as a by-product in the commercial extraction ofyttrium. In isolating dysprosium, most of the unwanted metals can be removed magnetically or by aflotation process. Dysprosium can then be separated from other rare earth metals by anion exchange displacement process. The resulting dysprosium ions can then react with eitherfluorine orchlorine to formdysprosium fluoride, DyF3, ordysprosium chloride, DyCl3. These compounds can be reduced using eithercalcium orlithium metals in the following reactions:[17]
3 Ca + 2 DyF3 → 2 Dy + 3 CaF2
3 Li + DyCl3 → Dy + 3 LiCl
The components are placed in atantalum crucible and fired in ahelium atmosphere. As the reaction progresses, the resulting halide compounds and molten dysprosium separate due to differences in density. When the mixture cools, the dysprosium can be cut away from the impurities.[17]
About 3100 tonnes of dysprosium were produced worldwide in 2021, with 40% of that total produced in China, 31% in Myanmar, and 20% in Australia.[32] Dysprosium prices have climbed over time, from $7 per pound in 2003, to $130 a pound in late 2010,[33] to $1,400/kg in 2011 and then falling to $240/kg in 2015, largely due to illegal production in China which circumvented government restrictions.[34] As of April 2025,[update] the price is around US$203/kg.[35]
Currently, most dysprosium is being obtained from the ion-adsorption clay ores of southern China.[36] As of November 2018[update] the Browns Range Project pilot plant, 160 km south east ofHalls Creek, Western Australia, is producing 50 tonnes (49 long tons) per annum.[37][38]
According to theUnited States Department of Energy, the wide range of its current and projected uses, together with the lack of any immediately suitable replacement, makes dysprosium the single most critical element for emerging clean energy technologies; even their most conservative projections predicted a shortfall of dysprosium before 2015.[39] As of October 2015,[update] there is a nascent rare earth (including dysprosium) extraction industry in Australia.[40]
Dysprosium is used, in conjunction withvanadium and other elements, in makinglaser materials and commercial lighting. Because of dysprosium's highthermal-neutron absorption cross-section, dysprosium-oxide–nickelcermets are used in neutron-absorbingcontrol rods innuclear reactors.[11][41] Dysprosium–cadmiumchalcogenides are sources ofinfrared radiation, which is useful for studying chemical reactions.[10] Because dysprosium and its compounds are highly susceptible to magnetization, they are employed in various data-storage applications, such as inhard disks.[42] Dysprosium is increasingly in demand for the permanent magnets used in electric-car motors[43] and wind-turbine generators.[44]
Neodymium–iron–boronmagnets can have up to 6% of the neodymium substituted by dysprosium[45] to raise thecoercivity for demanding applications, such as drive motors for electric vehicles and generators for wind turbines. This substitution would require up to 100 grams of dysprosium per electric car produced. Based onToyota's projected 2 million units per year, the use of dysprosium in applications such as this would quickly exhaust its available supply.[46] The dysprosium substitution may also be useful in other applications because it improves the corrosion resistance of the magnets.[47]
Dysprosium is one of the components ofTerfenol-D, along with iron and terbium. Terfenol-D has the highest room-temperaturemagnetostriction of any known material,[48] which is employed intransducers, wide-bandmechanical resonators,[49] and high-precision liquid-fuel injectors.[50]
Dysprosium is used indosimeters for measuringionizing radiation.[51] Crystals ofcalcium sulfate orcalcium fluoride are doped with dysprosium. When these crystals are exposed to radiation, the dysprosium atoms becomeexcited andluminescent. The luminescence can be measured to determine the degree of exposure to which the dosimeter has been subjected.[11]
Nanofibers of dysprosium compounds have high strength and a large surface area. Therefore, they can be used to reinforce other materials and act as a catalyst. Fibers of dysprosium oxide fluoride can be produced by heating an aqueous solution of DyBr3 and NaF to 450 °C at 450 bars for 17 hours. This material is remarkably robust, surviving over 100 hours in various aqueous solutions at temperatures exceeding 400 °C without redissolving or aggregating.[52][53][54] Additionally, dysprosium has been used to create a two-dimensionalsupersolid in a laboratory environment. Supersolids are expected to exhibit unusual properties, includingsuperfluidity.[55]
Dysprosium iodide anddysprosium bromide are used in high-intensitymetal-halide lamps. These compounds dissociate near the hot center of the lamp, releasing isolated dysprosium atoms. The latter re-emit light in the green and red part of the spectrum, thereby effectively producing bright light.[11][56]
Several paramagnetic crystal salts of dysprosium (dysprosium gallium garnet, DGG; dysprosium aluminium garnet, DAG; dysprosium iron garnet, DyIG) are used inadiabatic demagnetization refrigerators.[57][58]
The trivalent dysprosium ion (Dy3+) has been studied due to its downshifting luminescence properties. Dy-dopedyttrium aluminium garnet (Dy:YAG) excited in the ultraviolet region of the electromagnetic spectrum results in the emission of photons of longer wavelength in the visible region. This idea is the basis for a new generation of UV-pumped white light-emitting diodes.[59]
Due to its strong magnetic properties, dysprosium alloys are used in the marine industry's sound navigation and ranging (SONAR) system.[65][66] The inclusion of dysprosium alloys in the design ofSONARtransducers and receivers can improve sensitivity and accuracy by providing more stable and efficient magnetic fields.[67]
Like many powders, dysprosium powder may present an explosion hazard when mixed with air and when an ignition source is present. Thin foils of the substance can also be ignited by sparks or bystatic electricity. Dysprosium fires cannot be extinguished with water. It can react with water to produce flammablehydrogen gas.[68]Dysprosium chloride fires can be extinguished with water.[69]Dysprosium fluoride anddysprosium oxide are non-flammable.[70][71]Dysprosium nitrate, Dy(NO3)3, is a strongoxidizing agent and readily ignites on contact with organic substances.[12]
Soluble dysprosium salts, such as dysprosium chloride and dysprosium nitrate are mildly toxic when ingested. Based on the toxicity of dysprosium chloride tomice, it is estimated that the ingestion of 500 grams or more could be fatal to a human (cf.lethal dose of 300 grams of common table salt for a 100 kilogram human). The insoluble salts are non-toxic.[11]
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