Magnets Rare Earth - Different Types And How They Are Best Utilized

Magnets rare earth can be divided into two. Rare earth refers to the family of lanthanides, which in physics has a specific meaning,  namely it  refers to the elements with atomic numbers from 57 to 71. This group is known as f-block and has individually incomplete filling. They are unstable in their solid state, as each has seven unpaired electrons.  When spinning, this creates magnetism even greater than the one by ferrites, which previously was thought of as greatest of magnetism. The shift happened in the 1980s, no longer were ferrites on the top, as the rare earth variety gained momentum and eventually overtook them.

Ferrites are part iron oxide, part ceramic compounds.  The earthy cousins are superior because, first, they are, as mentioned, more magnetic. Secondly, they are less susceptible to demagnetization.  The coercivity, which notes the resistance of magnets to demagnetization, of ferrites is around 150, while it is between 600 and 2000 for rare earth varieties. Thus, when you need the material most magnetic and least prone to losing the magnetism, using rare earth is the best.    


Mass transit systems, such as bullet trains, high-rise elevators, roller coasters, and so on, all use rare earth magnets. However, within rare earth magnets, the two main types has differing characteristics making them suitable for different purposes.






The neodymium type can be found in more places and is the magnet used in big business since it is the most powerful magnet on earth.  However, neodymium is more in danger of rusting than the rare samarium-cobalt variety.  To compensate for this weakness, surface coating is applied in order to guard against corrosion.

The samarium-cobalt magnet is not without weaknesses.  It can  become brittle, therefore manufacturers tend to enclose it in some form of protection, such as glass. It is also a more expensive material, this applies whether we are talking over the counter or in the production stage. It has not been able to catch up to the popularity of its neodymium brother, mainly because of this fact. Some industries, however, still prefer using samarium-cobalt modules, as these perform better at extremely high temperatures, while the other works better at cool temperatures. Spinning a hard drives then, you could theoretically use neodymium, but samarium-cobalt would actually perform much better.


Magnets rare earth is a prime example of using physics to create superior products for mankind.  The famous physicist Albert Einstein might not, however, have been entirely pleased, as he was an well-known pacifist, that his popular formula was utilized to build the atomic bomb.  This doesn't change the fact though, that if he were here today, he would be ecstatic to experience the laws of magnetism being controlled and used to prevent fatal accidents on crowded city streets.