Terbium – Dysprosium – Holmium Dy Cf       Full table
General
Name, Symbol, Number	Dysprosium, Dy, 66
Chemical series	Lanthanides
Group, Period, Block	_ , 6 , f
Density, Hardness	8551 kg/m3, no data
Appearance	silvery white
Atomic properties
Atomic weight	162.500(1) amu
Atomic radius (calc.)	175 (228) pm
Covalent radius	no data
van der Waals radius	no data
Electron configuration	[Xe]6s²4f10
e- 's per energy level	2, 8, 18, 28, 8, 2
Oxidation states (Oxide)	3 (weak base)
Crystal structure	Hexagonal
Physical properties
State of matter	solid (ferromagnetic)
Melting point	1680 K (2565 �F)
Boiling point	2840 K (4653 �F)
Molar volume	19.01 ×10-6 m3/mol
Heat of vaporization	230 kJ/mol
Heat of fusion	11.06 kJ/mol
Vapor pressure	no data
Velocity of sound	2170 m/s at 293.15 K
Miscellaneous
Electronegativity	1.22 (Pauling scale)
Specific heat capacity	170 J/(kg*K)
Electrical conductivity	1.08 106/m ohm
Thermal conductivity	10.7 W/(m*K)
1st ionization potential	573.0 kJ/mol
2nd ionization potential	1130 kJ/mol
3rd ionization potential	2200 kJ/mol
4th ionization potential	3990 kJ/mol
Most stable isotopes
iso NA half-life DM DE MeV DP 154Dy {syn.} 3.0E+6 y α 2.947 150Gd 156Dy 0.06% 156Dy is stable with 90 neutrons 158Dy 0.10% 158Dy is stable with 92 neutrons 160Dy 2.34% 160Dy is stable with 94 neutrons 161Dy 18.91% 161Dy is stable with 95 neutrons 162Dy 25.51% 162Dy is stable with 96 neutrons 163Dy 24.90% 163Dy is stable with 97 neutrons 164Dy 28.18% 164Dy is stable with 98 neutrons
SI units & STP are used except where noted.

Dysprosium is a chemical element in the periodic table that has the symbol Dy and atomic number 66.

Contents

1 Notable characteristics 2 Applications 3 History 4 Occurrence 5 Compounds 6 Isotopes 7 Precautions 8 References 9 External links

Notable characteristics

Dysprosium is a rare earth element that has a metallic, bright silver luster, relatively stable in air at room temperature, but dissolving readily in dilute or concentrated mineral acids with the emission of hydrogen. It is soft enough to be cut with a knife, and can be machined without sparking if overheating is avoided. Dysprosium's characteristics can be greatly affected even by small amounts of impurities.

Applications

Dysprosium is used, in conjunction with vanadium and other elements, for making laser materials; its high thermal neutron absorption cross-section and melting point also suggest using it for nuclear control rods, dysprosium oxide (also known as dysprosia) with nickel cement compounds which absorb neutrons readily without swelling or contracting under prolonged neutron bombardment, is being used for cooling rods in nuclear reactors. Dysprosium-cadmium chalcogenides are sources of infrared radiation for studying chemical reactions; furthermore, dysprosium is used for manufacturing compact discs.

History

Dysprosium was first identified in Paris in 1886 by French chemist Paul �mile Lecoq de Boisbaudran; however, the element itself was not isolated in relatively pure form until after the development of ion exchange and metallographic reduction techniques in the 1950s. The name dysprosium is derived from Greek dysprositos, "hard to get at".

Occurrence

Dysprosium is never encountered as the free element, but is found in many minerals, including xenotime, fergusonite, gadolinite, euxenite, polycrase, blomstrandine, monazite and bastnasite, often with erbium and holmium or other rare earth elements.

Compounds

Nearly all dysprosium compounds are in the +3 oxidation state, and are highly paramagnetic. Dysprosium compounds include:

• Fluorides
  • DyF₃
• Chlorides
  • DyCl₂
  • DyCl₃
• Bromides
  • DyBr₂
  • DyBr₃
• Iodides
  • DyI₂
  • DyI₃
• Oxides
  • Dy₂O₃
• Sulfides
  • Dy₂S₃
• Nitrides
  • DyN

Isotopes

Naturally occurring dysprosium is composed of 7 stable isotopes, 156-Dy, 158-Dy, 160-Dy, 161-Dy, 162-Dy, 163-Dy and 164-Dy, with 164-Dy being the most abundant (28.18% natural abundance). 28 radioisotopes have been characterized, with the most stable being 154-Dy with a half-life of 3.0E+6 years, 159-Dy with a half-life of 144.4 days, and 166-Dy with a half-life of 81.6 hours. All of the remaining radioactive isotopes have half-lifes that are less than 10 hours, and the majority of these have half lifes that are less than 30 seconds. This element also has 5 meta states, with the most stable being 165m-Dy (t_� 1.257 minutes), 147m-Dy (t_� 55.7 seconds) and 145m-Dy (t_� 13.6 seconds).

The primary decay mode before the most abundant stable isotope, 164-Dy, is electron capture, and the primary mode after is beta minus decay. The primary decay products before 164-Dy are terbium isotopes, and the primary products after are holmium isotopes.

Precautions

As with the other lanthanides, dysprosium compounds are of low to moderate toxicity, although their toxicity has not been investigated in detail. Dysprosium does not have any known biological properties.

References

• Los Alamos National Laboratory – Dysprosium (http://periodic.lanl.gov/elements/66.html)

External links

• WebElements.com – Dysprosium (http://www.webelements.com/webelements/elements/text/Dy/index.html)
• EnvironmentalChemistry.com – Dysprosium (http://environmentalchemistry.com/yogi/periodic/Dy.html)
• It's Elemental – Dysprosium (http://education.jlab.org/itselemental/ele066.html)
• High-Res. pictures and details about Dysprosium metal (http://www.seltenerden.de?arg=zoom&art=238&element=Dy&linkid=ewiki-Dy) (German)

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