Why do magnets have magnetism? Why do they have magnetism?

Release Time:2020-06-03 Number of views:343

Matter is mostly made up of molecules, which are made up of atoms, which in turn are made up of Nuclei and electrons.

Inside the atom, electrons spin around and around the nucleus. Both movements of an electron produce magnetism.

But in most materials, the electrons move in different directions, in disorder, and the magnetic effects cancel each other out. Therefore, under normal conditions, most materials do not show magnetism and have no magnetic force to the outside.

Ferromagnetic materials such as iron, cobalt, nickel or ferrite are different. Their internal electron spins can spontaneously line up in a small range to form a spontaneous magnetic field called a domain.

Ferromagnetic material magnetization, the internal magnetic domain neat, uniform alignment, so that the magnetic strength, to form a magnet. The magnetizing process of the magnet is the magnetizing process of the Iron Block. The magnetized iron block and the magnet have attraction between different polarities, and the iron block is firmly "stuck" to the magnet. Let's just say the magnet is magnetic.

The so-called magnetic domain, magnetic material is the interior of a small region, each region contains a large number of atoms, these atoms of magnetic moments are as neatly arranged as a small magnet, but the atomic magnetic moments are arranged in different directions in different adjacent regions, and the interface between each domain is called domain wall.

Macroscopical object always has a lot of magnetic domain, so, magnetic domain magnetic moment direction is different, the result cancel each other, vector sum is zero, whole object magnetic moment is zero, it also can not attract other magnetic material.

 That is to say, the magnetic material does not show magnetism to the outside under normal circumstances. Only when a magnetic material is magnetized can it show its magnetism to the outside world.