World's First Room Temperature Superconductor Achieved Using Lead-Apatite Structure

Monday - July 31 2023, 05:27 UTC - 1 year ago

Greek researchers have successfully synthesized lead-apatite structure (LK-99) to create a room temperature superconductor. This major discovery could pave the way for high-current-density superconductors at room temperature and ambient pressure.

For the first time in the world, researchers (From Korea University, Sukbae Lee, Ji-Hoon Kim, Hyun-Tak Kim) have succeeded in synthesizing a 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.

NOTE: More charts of resistance is leaning towards this being a strong diamagnet and not a superconductor. The researchers were likely mistaken and not frauds. We’ve been getting excited over the years about superconducting materials that don’t even quite have to be cooled with liquid nitrogen, and this stuff is claimed to superconduct all the way up to room temperature and indeed up past the boiling point of water. Its critical temperature is said to be 127C (!) The phrase "boiling-water superconductor" is not one that I had ever used until yesterday.

Whether LK-99 itself becomes a big industrial material is open to question – one of the things you get from the characterization data is that LK-99 is not able to carry much current in its superconducting state at these high temperatures, and that’s a key property for many applications. That might not be surprising, either, because other superconductors generally carry less current density the higher the temperature gets (i.e., the closer to the critical temperature). But it has to be noted that this is indeed a polycrystalline material as synthesized, and that junctions between the different crystal domains can affect this profoundly. We also don’t have a feeling for how such a quantum-well superconductor behaves in general, if that’s how it works. If this is real, vast amounts of work will go into seeing if that current density can be increased by more careful synthesis and fabrication.

It’s a gigantic step to just show that such things can exist. That’s what will shake everyone up well before any applications come along, and if this reproduces, labs around the world will frantically start looking for quantum-well superconducting materials of their own. Who knows what could come out of that? Robust high-current-density room-temperature superconductors are right out of science fiction-land – could this sort of thing make them come true? We'll have to wait and see.