What causes an object to become a magnet?

Answer 1

All magnets are caused by the movement of electrons. No moving electrons = no magnet.

In a permanent magnet, several adjacent electrons have the same spin - they form a magnetic domain.

An electric current flowing in a circuit will form an electromagnet.

A.In a permanent magnet, the origin of the magnetic field comes down to an unpaired electron in one or more of the orbitals (electron shells) of the atoms in the material. All electrons produce magnetic fields due to either momentum or spin. Spin is the property primarily responsible for the magnetic field in a permanent magnet.

The Pauli exclusion principle requires that electrons occupying the same orbital be paired with electrons with opposite spin, and so the forces normally cancel each other out. An orbital with an unpaired electron means that its force will not be canceled and the atom will have an appreciable net magnetic field. The atoms in a molecule of iron, cobalt, or nickle all have unpaired electrons, which is why those materials are used to make strong magnets.

Inducing or running a directional current through a block of one of these materials will align the magnetic fields of the atoms. When the current is turned off, the atoms remain oriented and the material is said to be magnetized. To be clear, the molecules in the material were always "magnetized". It is only the alignment that matters.