The Meissner Effect demonstrated by levitating a magnet over a cuprate superconductor, that is cooled by liquid nitrogen Below some circumstances, like extremely low temperatures, some ceramics show high-temperature superconductivity (in superconductivity, "high temperature" signifies previously mentioned 30 K). The key reason why for this is simply not understood, but https://marioqhcxr.wikibriefing.com/3973028/considerations_to_know_about_what_is_ceramic_material