Limits RegistryPUBLIC RECORD
Limits RegistryMercury-based cuprate HgBa2Ca2Cu3O8+delta holds the record for highest confirmed ambient-pressure superconducting transition temperature at about 133-138 K, first reported in 1993 and still unsurpassed by any ambient-pressure material as of the mid-2020s — well above liquid-nitrogen temperature (77 K), making these cuprates practical to cool cheaply.
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Mercury-based cuprate HgBa2Ca2Cu3O8+delta holds the record for highest confirmed ambient-pressure superconducting transition temperature at about 133-138 K, first reported in 1993 and still unsurpassed by any ambient-pressure material as of the mid-2020s — well above liquid-nitrogen temperature (77 K), making these cuprates practical to cool cheaply.
The highest confirmed superconducting transition temperature of any material measured at ordinary atmospheric pressure (excluding high-pressure hydride superconductors that only superconduct under megabar compression).
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Limits Registry. LR-HIGHEST-CONFIRMED-SUPERCONDUCTING-TRANSITION-TEMP-AMBIENT-PRESSURE. Highest superconducting critical temperature at ambient pressure. 2026.