I'm not even sure they reversed the magnet polarity in this video, it seems they just removed the magnet and put it back, so there's no way to rule out a ferrom

I'm not even sure they reversed the magnet polarity in this video, it seems they just removed the magnet and put it back, so there's no way to rule out a ferromagnetic effect. Again, I just find it really hard to deduce anything from this footage, not saying it can't be a superconductor. I'm not even sure they reversed the magnet polarity in this video, it seems they just removed the magnet and put it back, so there's no way to rule out a ferromagnetic effect. I'm not sure either if LK-99 is a type-II superconductor but I would believe so given the papers I've read. Type-II superconductors aren't perfect diamagnets, they allow magnetic flux to penetrate the superconductor once you hit the first critical field, these flux vortices then get pinned at sites of defects where the energy requirement for breaking the superconductivity is lowest. That's what keeps a type-II superconductor levitating over a magnet, a type I superconductor or perfect diamagnet wouldn't do that. Then again I have never seen how e.g. a tiny YBCO flake (high Tc type-II superconductor) would behave if you put it in a beaker and dragged a Neodym magnet below it, so who knows.