neodymium magnets are a kind of rare earth magnets.They have the strongest magnetism, and if you handle them in wrong way, it's very dangerous.They are always called rare earth magnets because the elements of ndfeb magnets are the rare earth elements on the periodic table.But there are differences between ndfeb magnets and rare earth magnets.Rare earth magnets include several kinds of magnets, however ndfeb magnets are just one type.Nowdays, ndfeb magnets are the strongest magnets.
   Why ndfeb magnets are the strongest magnets,we should consider about the elements: Neodymium, Iron and Boron, they are also short for Nd-Fe-B,even if the small size of ndfeb magnets are very strong.
   How to identify the poles of ndfeb magnets:
   There are some good ways to distinguish the North and South poles of ndfeb magnet:
   1) The simplest method is to use a magnet which is marked the poles already. if the north of the magnet has been marked, then you put another magnet which you don't know the poles, if they attract, then the closer side of the unknown poles magnet will be south pole. vice versa. it's very easy to understand.There's a normal rule: the same poles of two magnets will repel each other, and different poles will attract each other.
   2) Take a magnetic compass and bring it close to the ndfeb magnet which you want to know the poles. the South pole of the compass will attract the North pole of the magnet and will repel the South pole of the magnet.
   3) Take one magnet and hold it with a string,then it will rotate freely,The North pole of the magnet will points the north.
   People pay more and more attention to ndfeb magnet for the following reasons:
   1) neodymium magnets are the strongest magnets of all the rare earth magnets;
   2) ndfeb magnets have a extremly high resistance to be demagnitized. This makes them very useful in many different industrial areas;
   3) if consider the same Br and sizes, ndfeb magnets have stronger magnetism than SmCo magnets or AlNiCo magnets,and the price is cheaper;
   4) there are still some disadvantages for ndfeb magnets, they are easily corroded, so we should coat them with Zinc or Nickel to protect them;
   5) another weakness is the working temperature for neodymium magnets are not very high, if the temperature is higher than 250 degree centigrade, we
can't use any ndfeb magnets.