Why do ferromagnets have domains?

Question

Electronics

How are particles of matter spontaneously magnetized? Does magnetization depend on the number of free electrons in a substance?
Can you explain in simple terms about magnetic domains? The Wikipedia definitions scare me as a newbie on the subject.

Answer 1

Learn the terms. You won't understand this without them.
Magnetization is determined not by the number of electrons, but by their interaction with the participation of nuclei. This is quantum mechanics, it is inherently complex; but without it, it is impossible to deal with these effects.
Magnetization occurs because an individual atom has a magnetic moment; and when two atoms interact, it is "cheaper" (in terms of energy) for them to be located unidirectionally. And the next atoms also stand in line.
However, with an increase in the number of atoms, the energy of the magnetic field grows quadratically. And at some point it turns out to be "energetically cheaper" to divide into zones of different magnetization - despite the fact that the boundary has an increased energy. These zones are magnetic domains.

Answer 2

https://ru.wikipedia.org/wiki/%D0%9C%D0%B0%D0%B3%D...