Dysprosium, isolated in 1886, derives its name from the Greek dysprositos meaning ‘hard to get’ and judging by its scarcity and price, it still is.
Dysprosium has a metallic, bright silver lustre. It is relatively stable in air at room temperature, but dissolves readily with the evolution of hydrogen, in mineral acids. The metal is soft enough to be cut with a knife and can be machined without sparking if overheating is avoided. It is generally found in small amounts in minerals such as xenotime, monazite and bastnaesite.
Dysprosium's physical characteristics can be greatly affected even by small amounts of impurities. It reacts with water and the halogens at higher temperatures and it has one of the highest magnetic strengths of the elements, especially at low temperatures.
Applications of Dysprosium:
- Magnets - Electromotive: Neodymium-iron-boron magnets, or Neo-Magnets, can have up to 6% of the neodymium substituted with dysprosium to rise the coercively or strength in demanding applications such as motors for hybrid electric vehicles. The dysprosium substitution also tends to improve the corrosion resistance of the magnets.
- Magnets - Electronics: Dysprosium is used in various data storage applications such as in compact discs. It is also one of the components of ‘Terfenol-D', along with iron and terbium, which has the highest room-temperature magneto resistance of any known material: a property whose use is employed in transducers, wide-band mechanical resonators and high-precision liquid fuel injectors.
- Energy: Because of dysprosium's high thermal neutron absorption cross-section, dysprosium oxide-nickel cements are used in neutron-absorbing control rods in nuclear reactors. Dysprosium also used in dosimeters for measuring ionizing radiation.
- Ceramics and Specialty Glass: Dysprosium is used in conjunction with vanadium and other elements in making laser materials.
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 by static electricity. Dysprosium fires cannot be put out by water.