We continue to review some of the most important materials in heat treatment and metallurgy.
Neodymium (chemical symbol: Nd)
Neodymium (Fig. 1) is a soft, bright, silvery-white metal that is considered to be mildly toxic and even harmful if it comes in contact with the eyes or skin. In addition, prolonged inhalation can also severely affect the respiratory system. It is one of the lanthanide family of rare-earth metals and forms a flaky oxide when exposed to air.
Neodymium was first identified in 1885, in Vienna, by Austrian scientist Carl Auer von Welsbach, who 14 years earlier had mistakenly discovered “didymium,” a substance that was incorrectly identified by Swedish chemist Carl Mosander as a new element in 1841. Welsbach realized that didymium was actually a mixture of two entirely new elements, which he named neodymium and praseodymium. Welsbach reacted “didymium to form nitrate salts, which he then fractionally crystallized from nitric acid to yield pink neodymium and greenish-brown praseodymium salts. Neodymium was artificially synthesized in 1925.
Neodymium sees a wide range of uses in a variety of different industries. Some common applications include permanent magnets (Fig. 2), where neodymium is combined with iron and boron; solid-state YAG lasers, where neodymium is doped with yttrium-aluminum-garnet; electronic devices (loudspeakers, microphones, motor generators); mobile phones; car windshield wipers; wind turbines; and electric guitars and similar musical instruments. It also finds uses in laser pointers for treating skin cancer, eye problems and cosmetic surgery. Some neodymium salts are even used in the coloring of glazes and enamels.
Here are a few important facts about neodymium.[1-2]
- Atomic number: 60
- Atomic weight: 144.242
- Melting point: 1298 K (1025°C or 1877ºF)
- Boiling point: 3347 K (3074°C or 5565°F)
- Density (solid): 7.01 grams per cubic centimeter
- Phase at room temperature: Solid
- Element classification: Metal
- Period number: 6
- Group number: none
- Group name: Lanthanide
- Electron configuration: [Xe] 4f46s2