Under the action of the magnetic field generated by the magnet, the arrangement of atomic magnetic moments of iron will change from chaos to order, thus being magnetized and generating a magnetic field. In this way, electromagnetic force can be generated between the magnet and iron, so the magnet can attract iron.
Magnets can be divided into "permanent magnets" and "non-permanent magnets". Permanent magnets can be natural products, also known as natural magnets, or artificial. Non-permanent magnets, such as electromagnets, are magnetic only under certain conditions.
The extended data magnet is not invented by people, but a natural magnet. The ancient Greeks and China discovered that there was a naturally magnetized stone in nature, called a "magnet". This kind of stone can magically pick up a small piece of iron and swing it at will and always point in the same direction.
Early navigators used this magnet as their earliest compass to tell directions at sea. It should be China who first discovered and used magnets, that is, making a compass with magnets is one of the four great inventions in China.
After thousands of years of development, magnets have become a powerful material in our life today. By synthesizing alloys of different materials, we can achieve the same effect as magnets and improve the magnetic force. /kloc-artificial magnets appeared in the 0/8th century, but the process of making stronger magnetic materials was very slow, and Al-Ni-Co was not produced until the 1920s.
Subsequently, ferrite was manufactured in 1950s and [rare earth magnets [including NdFeB and SmCo]] was manufactured in 1970s. At this point, magnetic technology has developed rapidly, and ferromagnetic materials have also made components more miniaturized.
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