Neodymium was discovered by Welsbach, a German chemist, in 1886 when he separated it and the element praseodymium from a compound known as didymium. He named neodymium for neo meaning new and didymos meaning twin. Praseodymium was named as "green twin" for the colour of its oxide.
Neodymium metal has a bright silvery colour and metallic lustre. It is a reactive rare-earth that quickly tarnishes in air, forming an oxide that spalls off and exposes the metal to further oxidation. It is never found in nature as a free element. Rather, it occurs with other rare earth elements in minerals such as monazite (Ce,La,Th,Nd,Y) PO4) and bastnaesite (Ce,La,Th,Nd,Y) (CO3)F) which are the main rare earth minerals that have been mined in India, the United States, and China.
APPLICATIONS OF NEODYMIUM
Rare Earth Magnets: Neodymium magnets (Nd2Fe14B) or ‘neo-magnets' are the strongest permanent magnets known. Although mechanically fragile, they are cheaper, lighter, and stronger than the better known, rare earth, samarium-cobalt magnet. Neo-magnets appear in products such as microphones, loudspeakers, in-ear headphones (ear buds and hearing aids), guitar pick-ups, computer hard drives, and "voice coils" for reading computer hard drives. They are found throughout hybrid cars, in industrial motors, air conditioners, elevators, industrial tools, and the new, energy efficient, wind and tidal electricity turbine generators.
Like all magnets, neo-magnets lose their magnetic strength with rising temperature. The most powerful grades have maximum working temperatures at a relatively low 80o C (176o F) making them difficult to use in hybrid and electric automotive applications. High-temperature grade neo-magnets however, can be made by introducing the rare earths terbium (TB) or dysprosium (Dy) to the "neo" alloy and make magnets that will operate at up to 200oC, and thus enable the electric car.
The production of a rare earth magnet, starting from mining of a rare earth to its final installation in a green car, may entail as many as 8 different processes by as many as 5 different manufacturers.
Glass and Ceramics: Neodymium glass is becoming widely used in incandescent light bulbs to provide a more ‘natural' light, as it filters out yellow wavelengths and results in a whiter light more like sunlight. These same light filtering abilities see neodymium used in welding and glass-blowing eye protection and a neodymium specialty glass has been patented for use in automobile rear-view mirrors to reduce glare at night.
Neodymium also colors glass in delicate shades ranging from pure violet through wine-red and warm grey, and is used to stop green coloration caused by iron contamination in the glass melt. Neodymium salts are further used as colourisers for enamels and glazes. In cathode ray tubes (CRTs) neodymium enhances the contrast between red and green colours.
Science and Medical: Neodymium is used as a dope in yttrium- aluminum-garnet (YAG) lasers for medical applications, drilling, welding and material processing.
Naturally occurring neodymium isotopes are used by geologists to describe the origins of different magmas, and samarium-neodymium isotopes can be used to determine the age of rocks and meteorites.
Neodymium has an unusually large specific heat capacity at the temperature of liquid-helium, so is useful in cryocoolers.
|Neo-Magnet n a Bracket From
Hard Drive Magnets
|In Earphones||Incandescent Light bulb|
|Laser Glass||Neo magnet can carry 1300 x its weight|