> But I think they buried the lede a little. Ferromagnetism is novel and unexpected in this material system, and might be interesting. But strong diamagnetism even more so
> Even if the diamagnetic fraction is the entire sample (appears less) then it would be the second-strongest diamagnet known (and pyrolytic graphite's diamagnetism is very anisotropic). In both Bi and graphite, diamagnetism results from unusual band topology. It's not common
> Overall, some evidence that as-synthesized nominally Pb_10-xCu_x(PO4)O ("LK-99") is magnetically quite unusual, with different fractions showing soft ferromagnetism and strong diamagnetism
> But I think they buried the lede a little. Ferromagnetism is novel and unexpected in this material system, and might be interesting. But strong diamagnetism even more so
> Even if the diamagnetic fraction is the entire sample (appears less) then it would be the second-strongest diamagnet known (and pyrolytic graphite's diamagnetism is very anisotropic). In both Bi and graphite, diamagnetism results from unusual band topology. It's not common
> Overall, some evidence that as-synthesized nominally Pb_10-xCu_x(PO4)O ("LK-99") is magnetically quite unusual, with different fractions showing soft ferromagnetism and strong diamagnetism