The Meissner effect demonstrated by levitating a magnet higher than a cuprate superconductor, that's cooled by liquid nitrogen Less than some problems, such as really low temperatures, some ceramics exhibit high-temperature superconductivity (in superconductivity, "high temperature" suggests above 30 K). The explanation for it's not recognized, but there are two https://troykuelt.wikiannouncement.com/9668957/getting_my_techniques_in_ceramics_to_work