What are Magnets Made Of?

I Like the Way You Move

We'll save the talk about sub-atomic particles like quarks for another day; the electrons are what we're interested in here. Why? Because the movement and positions of electrons are what create a magnetic field around an object.

You might be wondering: if everything has atoms, and atoms have electrons, does that mean everything has a magnetic field? Technically, yes! However, most magnetic fields are too weak to detect. That's why human beings aren't magnets, and we can go around without bumping into everything.

Magnets Inside of Magnets

But even atoms themselves have magnetic fields—really, really tiny ones. Again, it’s because of the way the electrons are positioned and oriented. Their position means that the magnetic field has an orientation—the force acts in a certain direction.

In certain materials, the atoms' little magnetic fields tend to line up so that they're facing the same way. Together, they combine to create a much stronger field that covers the whole piece of material, which makes that piece a magnet.

The north pole and south pole of a magnet refer to the way all of those little magnetic fields tend to line up. Planet Earth itself is one big, giant magnet, thanks to all of the molten metal churning at its core. That’s why a free-floating magnet like the needle of a compass points north. Its magnetic field is lining up with the Earth’s!

So now that your head is packed full of ideas, let's put those ideas to use and answer the question you really came here to know.

Feel the Power!

Those powerful magnets in your science labs had to come from somewhere, right? Unlike temporary magnets, the atoms' magnetic fields in permanent magnets tend to stay oriented the same way, or at least take a really long time to fall out of alignment (like teeth ten years after someone stops wearing a retainer).

There's actually a permanent magnet that can be found in nature. It's a particular form of iron ore called magnetite. Explorers of centuries past used to make their compass needles from it. They would use the fact that magnetite compass needles always pointed north as a guide home. That's why they referred to magnetite as lodestone, after the idea of a "leading stone."

These days, it would be way too expensive to mine magnetite just to make refrigerator magnets, so companies make permanent magnets out of combinations of metals called alloys, which they magnetize by placing next to other strong magnets. Some permanent magnet alloy materials include:

› Alnico, a combination of aluminum, nickel, and cobalt
› Ticonal, which is alnico further combined with titanium
› Strontium ferrite
› Samarium cobalt

In each case, the ferrous metal is combined with another material that helps keep its atoms' magnet fields pointing the same way. Aluminum is great for that!

Alnico is flexible and can be used in unusually shaped magnets. Additionally, many permanent magnets are used in radio antennas and other electronics equipment.