Wel, i guess it sounds like a simple question, and it is in a way.
Ferrites, i know they where the first to pop into my mind.
I am doing some background reading about magnetism, various forms of magnetism like diamagnetic, ferromagnetic, etcetera.
Back at school i had read about the weiss domains.
I have to do a little more background reading on
I do find that interesting, firewolfsm what you mentioned.
That magnetic fields are a form of photons. It does make sense.
I saw this movie of plasma flowing on the magnetic fieldlines flowing. I wonder if that is the case, a form of entanglement that would look like a string of photons connected.