View source for Neodymium

'''Neodymium '''is a [[lanthanide]] with the symbol '''Nd''' and atomic number 60. Also classified as a [[rare earth metal]], it is a silvery solid that tarnishes quickly in air and will completely corrode to a pink oxide powder if stored improperly. Its most common use is in high-strength [[Neodymium iron boron magnet|neodymium magnets]]. As a tripositive ion, neodymium has unusually narrow absorption bands and will undergo color changes depending on the light source.

==Properties==
===Physical properties===
Neodymium is a silvery metal that is about as dense as [[tin]]. Older samples that have been exposed to air show corrosion, which will appear bluish. Although the metal is known for its use in powerful magnets, it is only slightly [[Paramagnetism|paramagnetic]] and cannot be lifted by a neodymium magnet. It may be possible to observe the magnetism by placing a small piece on a styrofoam block and allowing it to move toward a magnet.

Neodymium salts undergo large and dramatic color changes under different light sources. Under incandescent light or sunlight, which consist of continuous spectra, neodymium salts generally appear pink or purple. Fluorescent lighting consists of only a few specific energies of light which do not match the absorption bands of neodymium salts, thus causing the compounds to appear colorless. [[Holmium]] compounds will undergo similar color changes.

===Chemical properties===
Neodymium metal is rather reactive, and a centimeter-sized sample will corrode within a year on exposure to air. Thus, the metal must be stored under oil or in an ampoule filled with [[argon]]. The metal reacts only slowly with water, but reacts vigorously with acids and the halogens to form neodymium salts. Most neodymium salts are soluble in water except for the fluoride and oxalate. [[Neodymium oxide]] and [[Neodymium hydroxide|hydroxide]] are insoluble in water, but will absorb [[carbon dioxide]] from the air to form [[Neodymium carbonate|neodymium carbonate]]. All three of these compounds are insoluble in water, but will readily dissolve in acids.

[[Neodymium sulfate]] is notable for its inverse solubility curve, which causes the salt to precipitate at high temperatures. It is nearly impossible to redissolve after being precipitated. The double sulfate of potassium and neodymium is less soluble than neodymium sulfate itself. Different preparations of neodymium sulfate have given different colors, possibly due to the formation of acid and basic [[sulfate]]s.

Most lanthanides do not form complexes easily, but there is evidence for a possible chloride complex.

==Availability==
Pure neodymium metal can be bought from [http://elementsales.com/pl_element.htm#nd Metallium]. It is sold as 5 and 50 gram sizes, as well as rods, ampoules, and coins.

==Preparation==
The most common source of neodymium is [[Neodymium iron boron magnet|neodymium magnets]]. It's difficult, however, to extract the neodymium from the magnets, and a procedure to produce pure neodymium metal from [[neodymium fluoride]] with either [[calcium]] or [[lithium]] as the reductor is still in development.

==Projects==
*Color changing crystals
*Color changing glass
*Extracting neodymium from magnets

==Safety==
===Storage===
Neodymium metal must be stored away from air and water. [[Ampoule|Ampouling]] the metal is a viable long-term storage solution. Storing the metal under [[mineral oil]] is an ideal short-term solution, but air will still diffuse through the oil anyway. Unlike [[europium]], the reaction with water is not violent.

===Toxicity===
Neodymium compounds do not appear to be very toxic. They act similarly to [[calcium]] ions within the body. However, research on the toxicity neodymium compounds is not complete, and they should be handled with general safety precautions in place.

===Flammability===
Neodymium is somewhat flammable and may spark when struck. Powdered neodymium may ignite very easily. Class D [[fire extinguishers]] should be used against neodymium fires. Water may aggravate a neodymium fire and should never be used.

==References==
<references/>
===Relevant Sciencemadness threads===
*[http://www.sciencemadness.org/talk/viewthread.php?tid=14145 The trouble with neodymium...]
*[http://www.sciencemadness.org/talk/viewthread.php?tid=24851 Two times neodymium sulfate, different colors]

[[Category:Elements]]
[[Category:Metals]]
[[Category:Rare earth metals]]
[[Category:Lanthanides]]
[[Category:Reducing agents]]
[[Category:Materials that react with water]]
[[Category:Materials unstable in acidic solution]]
[[Category:F-block]]
[[Category:Air-sensitive materials]]