Neodymium magnet is also called NdFeB magnet, which is the strongest magnet at present, and it can absorb 640 times of its own weight, so it is called strong magnet. Its high hardness and stable performance are commonly used in electronic products, such as hard disk, cell phone, headphones, etc.
Note that neodymium magnets are sintered, while ordinary magnets are cast, so the surface is easy to rust because of the neodymium and iron in the material, so you need to do some protective plating treatment, which is one of its disadvantages.
A magnet as we know it is an object that repels and attracts each other. The magnet is composed of iron, nickel and cobalt, which itself has a magnetic distance from the internal structure in the same direction, one end of the north pole (N pole) and one end of the south pole (S pole).
So why are there many objects in nature that are not magnetic? The magnetic material in iron, nickel, and cobalt is different in that the electrons within it are spontaneously arranged in the same direction, which strengthens the magnetism and constitutes a magnet.
The magnet attracts the iron in the process of absorbing the iron, and the magnet "sticks" to the iron, so we say that the magnet is magnetic, that is, the magnet can absorb iron but not aluminum, copper and other objects, the internal structure of different metals is different. The unit of magnetic induction is Tesla, abbreviated as Ter (T).
Magnets are divided into permanent magnets and non-permanent magnets, permanent magnets are natural products that can maintain magnetic properties for a long time and are not easily demagnetized, such as magnetite. Non-permanent magnets require certain conditions to become magnetic.
Natural magnets were discovered by humans 5000 years ago.
2300 years ago, Chinese people ground the natural magnet into a spoon and put it on the smooth ground, under the action of geomagnetism, the spoon handle guide, the world's first compass.
1000 years ago, the Chinese made the world's first compass by rubbing an iron bar with a magnetic bar to magnetize it.
Around 1100, the Chinese made a magnet compass by connecting a magnet needle and an azimuth disk together, and used it for navigation.
In 1820, Danish physicists discovered that electric current induced magnetism.
In the 1930s, Japan discovered a new magnet with a mixture of nickel, aluminum and cobalt.
In the 1970s, Japanese scientists invented neodymium magnets, which were called "permanent magnets".