Magnets are made up of atoms such as iron, cobalt and nickel. Their atoms have special internal structures and have their own magnetic moments. Magnets can generate magnetic fields and attract ferromagnetic substances, such as iron, nickel, cobalt and other metals.
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.
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Use of similar magnets:
1, NdFeB permanent magnet is a modern permanent magnet with strong magnetism and is widely used.
Mainly used in electroacoustic, permanent magnet motor, communication, automotive electronics, magnetic machinery, aerospace, computer, household appliances, medical equipment, office automation, toys, packaging boxes, leather products, magnetic accessories and other fields.
2. Permanent magnet ferrite is used as a permanent magnet in electric meters, generators, telephones, loudspeakers, television and microwave equipment, and also used in tape recorders, pickups and loudspeakers, as well as magnetic cores of various instruments, and electronic equipment such as radar, communication, navigation and telemetry.
3. Sm-Co magnet can work up to 300 degrees, and has corrosion resistance and oxidation resistance. At present, it has been widely used in detector, generator, radar, instrument and other precision science and technology fields.
4. Al-Ni-Co magnet is resistant to high temperature and corrosion. Mainly used in motors, sensors, medical instruments, hand tools, loudspeakers and various instruments.
Reference source; Baidu encyclopedia-magnet