12.0 Dysprosium physical
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.
Atomic Number: 66.
Discovery: 1886 by P.É. Lecoq de Boisbaudran at Paris, France.
Name: Greek and means: difficult accessible.
Ore: xenotime, fergusonite, gadolinite, euxenite, polycrase, blomstrandine, monazite and bastnasite.
1. Lasers: in conjunction with vanadium and other elements.
2. Light: DyCd chalcogenides infrared radiation.
3. Lamps: DyI3 is used in halogen lamps.
4. magnets: NdFeB is a strong magnet; Dy raises the Coercion power and can be used at high temperatures.
5. CD disks.
6. CaSo4 or CaF2 + Dy are used to measure neutron or gamma radiation, it light then under heat.
7. Neutron absorption in nuclear reactors: 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.