We all use a neodymium magnet in one form or the other; we just don’t know that we do. There are so many uses and advantages of this amazing piece of human invention of which we are unaware of. One can easily find a neodymium magnet in a hard disk of a computer, headphones, and loud speakers to name a few. And these magnets are immensely powerful and enable us to do things where normal iron or ferrite magnets prove ineffective.
So what are neodymium magnets? Are they a Martian metal that came from outer space? To your disappointment, there is no such conspiracy theory. It is a rare earth magnet – an alloy comprising of elements such as Iron, neodymium and boron. The chemical formula for this unique alloy is Nd2Fe14B. More often one is likely to find crystalline structures in tetragonal shape when it comes to a neodymium magnet. This alloy is easily the strongest permanent magnet available
This neodymium magnet compound was discovered by General Motors Corporation, China Academy of Science and Sumitomo Special Metals in 1982. At that time there was a great need to find a suitable cost effective replacement for SmCo permanent magnets because of its rising costs.
Today the these magnets are manufactured via two production forms – sintered (powdered) and bonded magnet process. Approximately 45000 to 50,000 tons of sintered magnets are produced every year in comparison to 5500 tons of bonded magnet. The difference can be attributed to the demand and supply issue. The remanence i.e. the measure of strength of magnetic field of a magnet is high for a sintered magnet. The Curie temperature (named after Pierre Currie, famous French physicist and husband of Marie Curie) is the temperature at which the magnet loses its magnetism is same for both forms of neodymium magnets (approx 310 to 400o C). The Curie temperature of these magnets can be increased to 800o after alloying them with terbium and dysprosium.
The neodymium rare earth magnets are also known as neodymium iron boron magnets. No prizes for guessing why. Other popular names by which it is referred by is neodymium rare earth magnets. The unique aspect about these magnets is that they have an exceptionally high resistance to get demagnetized. This makes them very useful for various mechanical as well as industrial applications. As a small size magnet form is very powerful, the neodymium magnet are portable. And probably the best aspect is they are affordable making them perfect for lab experimentation and research. One can easily find neodymium disc magnets and neodymium magnets.
The downside of these magnets is that they are very corrosive in nature; hence need to be handled with absolute caution. A couple of these magnets used with little care can easily snap your finger. So it needs to be used with caution and attention. They can catch fire at high temperatures but work well in conditions where low temperatures are maintained.