The First Room-Temperature Ambient-Pressure Superconductor
arxiv.org
For the first time in the world, we succeeded in synthesizing the room-temperature superconductor ($T_c \ge 400$ K, 127$^\circ$C) working at ambient pressure with a modified lead-apatite (LK-99) structure. The superconductivity of LK-99 is proved with the Critical temperature ($T_c$), Zero-resistivity, Critical current ($I_c$), Critical magnetic field ($H_c$), and the Meissner effect. The superconductivity of LK-99 originates from minute structural distortion by a slight volume shrinkage (0.48 %), not by external factors such as temperature and pressure. The shrinkage is caused by Cu$^{2+}$ substitution of Pb$^{2+}$(2) ions in the insulating network of Pb(2)-phosphate and it generates the stress. It concurrently transfers to Pb(1) of the cylindrical column resulting in distortion of the cylindrical column interface, which creates superconducting quantum wells (SQWs) in the interface. The heat capacity results indicated that the new model is suitable for explaining the superconductivity of LK-99. The unique structure of LK-99 that allows the minute distorted structure to be maintained in the interfaces is the most important factor that LK-99 maintains and exhibits superconductivity at room temperatures and ambient pressure.

Abstract

For the first time in the world, we succeeded in synthesizing the room-temperature superconductor (Tc≥400 K, 127∘C) working at ambient pressure with a modified lead-apatite (LK-99) structure. The superconductivity of LK-99 is proved with the Critical temperature (Tc), Zero-resistivity, Critical current (Ic), Critical magnetic field (Hc), and the Meissner effect. The superconductivity of LK-99 originates from minute structural distortion by a slight volume shrinkage (0.48 %), not by external factors such as temperature and pressure. The shrinkage is caused by Cu2+ substitution of Pb2+(2) ions in the insulating network of Pb(2)-phosphate and it generates the stress. It concurrently transfers to Pb(1) of the cylindrical column resulting in distortion of the cylindrical column interface, which creates superconducting quantum wells (SQWs) in the interface. The heat capacity results indicated that the new model is suitable for explaining the superconductivity of LK-99. The unique structure of LK-99 that allows the minute distorted structure to be maintained in the interfaces is the most important factor that LK-99 maintains and exhibits superconductivity at room temperatures and ambient pressure.

https://doi.org/10.48550/arXiv.2307.12008

  • mkhoury
    2·
    11 months ago

    I think there’s a decent chance this new material could be mass produced if the superconductivity holds up. The synthesis seems pretty straightforward - just a solid state reaction at high temp using commercially available stuff like PbO and Cu. No crazy high pressures needed either.

    The key strained interfaces are made by substituting some Cu for Pb, so they’d need good process control to get that 0.48% shrinkage right every time. And you’d need access to testing gear like XRD and SQUID to validate the superconductivity, which might limit who can manufacture it at first.

    But on the whole, seems like existing ceramic production lines could likely be adapted to churn out boatloads of this material if there’s demand. The superconductivity at 400K would be a total game changer if confirmed. Fingers crossed they can work out any kinks in scaling up production, because I’d love to see some real world applications!

    • schroedingershat@lemmy.world
      3·
      11 months ago

      And you’d need access to testing gear like XRD and SQUID to validate the superconductivity, which might limit who can manufacture it at first.

      Is this needed for a production process? If you can fill it with current to the target field strength and come back in a day then it does the thing, nobody needs to care about some specific test.

      • mkhoury
        2·
        11 months ago

        I mean you wouldn’t need to test every piece of material coming out of your production line, but you might want to run them on some representative sample to ensure the consistency and quality of your production process. Small changes in your production process can veer you away from perfect superconductivity, and so you want to test at a high enough resolution to ensure it’s working as expected.