What Are the Differences Between Ferrous and Non-Ferrous Magnets?

[Stevay]

I have a quick question here, and essentially, I'm wondering what are the differences between a ferrous magnet (more specifically, iron) and a non-ferrous magnet? How would you distinguish between the two?

Thanks in advance; any help would be greatly appreciated.

 

[michael376071]

I think ferrous simply means iron like you said, or containing iron, usually they are magnetic substances, but I recall that some non-ferrous materials can also be strong magnets.

 

[Dirac]

Ferro Magnets

Imagine electrons orbiting the atom. As they do so they also spin, since they are charged particles they produce magnetic inertia and a tiny electric current and so this produces a tiny magnetic field. In some atoms, or in fact materials the magnetic effects of such electrons cancel; although in ferro magnetic materials, they do not. In such cases these atoms line up to produce a very strong magnetic field.

A way by which you could make these atoms line up is to put a ferro magnetic core inside a solenoid, through which a current is being passed. The atomic magnets inside the core line up along the uniform lines of flux of the solenoid as to produce such effect.

When the current is switched off, if the core was steel the atoms would remain in the latter position. If it was iron, the atoms would have had enough vibrational energy to move away from the described "line". As you can see an iron core is only a permanent magnent when current is being passed through it.

There are not a lot of permanent magnets in nature, mainly metallic cores. We define ferro magnetic materials to be those which have the properties that could allow them to become permanent magnets, just like the above described steel and iron.

Dirac.

 

[gfwhell]

If the metal iron, and its oxides are influenced by magnetism
How does aluminum compare? The metal can be "motivated" in an AC field, how about its Oxide? Both oxides are "non conductors"