The way a magnet works is determined by its overall atomic structure. Every atom is made up of negative electrons circling around positive protons and neutrons (called a nucleus), which are effectively microscopic magnets with north and south poles.
The electrons of a magnet move around the protons to create an orbital magnetic field.
Magnets have what is known as a half shell of electrons; in other words, they are not paired up like other materials. These electrons then line up, which creates a magnetic field.
All atoms align in groups which are known as crystals. The ferromagnetic crystals then align themselves to their magnetic poles. In a non-ferromagnetic material, on the other hand, they are randomly placed to cancel out any magnetic properties they may have.
A collection of crystals will then line up into domains, which are then all aligned in the same magnetic direction. The more domains that point in the same direction, the greater the magnetic force will be.
When a ferromagnetic material comes into contact with the magnet, the domains in this material align themselves with the domains in the magnet. Non-ferromagnetic materials do not move into alignment with the magnetic domains and stay in a random formation.
Attracting ferromagnetic materials
By attaching a ferromagnetic material to a magnet, a closed circuit is formed by the magnetic field travelling from the north pole, through the ferromagnetic material, and then to the south pole.
The attraction of a ferromagnetic material to a magnet, and its ability to hold onto to it, is referred to as the magnet’s pull force. The larger the pull force of the magnet, the more material it can attract.
A magnet’s pull force is determined by a number of different factors:
How the magnet has been coated
Any damage which may have occurred to the surface of the magnet e.g. rust
The thickness of ferromagnetic material (attaching to a piece of ferromagnetic material that is too thin will make the magnetic pull weaker by trapping the magnetic field lines).