eli5 Why do magnetics lose magnetism when they are heated up?


eli5 Why do magnetics lose magnetism when they are heated up?

In: Physics

Every atom has its own field that kinda aligns with the surrounding atoms in magnets, so altogether they add up to the object’s magnetic field. As they heat up, they get more and more energy and start to wiggle around until those fields aren’t all aligned. When they lose that alignment, they start interfering with each other so the big magnetic field gets weaker and weaker until it’s all a mess, or until something comes and realigns them.

Basically a magnet is made my putting hot or even liquid iron into a magnetic field where it solidifies. In that hot/liquid form the iron atoms can align with the magnetic field, so they all face the same direction. After the iron solidifies, the atoms can’t move around anymore to rearrange themselves. They stay, all in the same direction, which makes it a magnet. But if you heat that magnet up again, the atoms can move again, rearrange themselves in all directions and now all you have is a regular piece of iron.

I didn’t know that. Does the same thing happen if you freeze them?

At a molecular level, a magnetic object is made up electrons being held in a specific shape by the object’s internal bonds. One pole of the magnet would have almost all of the electrons while the other has almost none. This imbalance is what creates the magnetic field.

If you heat an object up, the bonds inside the object start to dissolve and things inside them can start to move around. Without the structure of the bonds to hold them in place, the electrons try to get as far away from each other as possible, resulting in them being evenly distributed inside the object. Without concentration of electrons to create it, the magnetic field goes away.