Last week it was claimed that a material that would be superconducting at  normal pressure has been found.  This substance known as LK-99 was alleged to be superconducting at normal atmospheric pressure and "room temperatures.  This would mean being able to say, make a superconducting power grid that could transport electricity without loss, or cheap superconducting magnets for maglev vehicles or particle accelerators etc. Since writing this story more than one team has reproduced the diamagnetic looking effect in which samples of LK-99, both big and small, all lean to one side in a characteristic way. The sought for Meissner effect would not do that, at least not in a way that is the same no matter how big the sample is. I am a theoretical astrophysicist, materials are not my specialty, I could be wrong, but I did learn about and work with superconductors as a student. This does not look like the Meissner effect. 

Two formal scientific efforts to reproduce the result have been reported on in formal papers submitted to the physics arXiv. (One of if not the oldest such archive of open access science on the internet.) 

So far the results are negative.

According to Kapil Kumar, N.K. Karn and V.P.S. Awana:

Our results on the present LK-99 sample, being synthesized at 925∘C, as of now do not approve the appearance of bulk superconductivity at room temperature. Further studies with different heat treatments are though, yet underway.







 According to Li Liu, Ziang Meng, Xiaoning Wang, et al : 

 In addition, when a pressed Pb10-xCux(PO4)6O pellet is located on top of a commercial Nd2Fe14B magnet at room temperature, no repulsion could be felt and no magnetic levitation was observed either. These results imply that the claim of a room-temperature superconductor in modified lead-apatite may need more careful re-examination, especially for the electrical transport properties.







 Another team has been attempting to stream, at least parts of, their attempt to reproduce this claim, on Twitch. 

https://www.twitch.tv/andrewmccalip   
 

Every time you hear a claim about a game changer like this, there is a 99.5% chance it is an over claim and will never be reproduced.  (Unless it's me.) 

From Cold fusion to super conductivity, to aliens a claim that we are 100% sure of any of those things is probably nonsense.  All these things are within the laws of physics but observing them is unlikely.  Serious science in any field will be stated in a probabilistic way.   If you hear "researchers think they may have found Applied Unobtainum, and Aliens, on Pandora but they need more study"; Then believe it. 

Superconductivity has been seen at very low temperatures for a long time.  Super conductivity has also been shown to exist at high pressures.  The problem is this make it not especially useful outside of very specific applications.  i.e. the Superconducting magnets in a particle accelerator.   That and other very science tech things.   Not something that could transmit power to your house without loss. 

The reason it is so hard is that superconductivity relies on pairs of electrons forming.  When these electrons form pairs.  Electrons are Fermions, particles with a property called spin, that comes in quantities of + ℏ/2 and -ℏ/2  (If ℏ is set =1 then +1/2 -1/2). As such these obey something called the Pauli Exclusion Principle.  They can't be in the same principal quantum state at the same time, in the same place ... They are what we think of as a matter.  When these pair up their spins will cancel to 0.   Particles with a spin of 0,1, or 2 are what are called Bosons.  So, things like the Higgs field (spin 0), Photons (spin 1) and gravitons (spin 2 theoretically), which can be in the same state, at the same time, in the same place.  These are particles we think of as energy.   

When electrons form a Cooper pair, they can conduct through the super conductor with 0 resistance due in part to the spin of the pair being 0.  The pair will act as if it was a boson.  A similar effect has been observed in Helium 3 where pairs of atoms would form, and we'd see fluid flow with no internal viscosity. 

There is a lot of evidence for these things close to 0 Kelvin. There is some evidence for them at 10,000 atmospheres of pressure.  So far room temp superconduction has not been proven and reproduced.  

This claim for 273 ish Kelvin and 1 atm of pressure ... is extraordinary.  If they are right they have Nobel prize.  SO far they do not seem to have been right.  I look forward to being wrong about that, since a room temp super conductor would advance technology by leaps and bounds.   

This video has video of that supposed superconductor being tested, and you can see why we are skeptical. 


This video demonstrates WHY it is not enough to show levitation but one has to demonstrate the characteristics of Meissner effect levitation.  Especially if Flux pinning is claimed.  If it is flux pinned then the supercondcutor can be suspended upside down.  IT can be moved very VERy stably. 


While with flux pinning it would be this stable. 

Sources

Synthesis of possible room temperature superconductor LK-99:Pb9Cu(PO4)6O
Kapil Kumar, N.K. Karn, V.P.S. Awana (CSIR PL,INDIA)  https://arxiv.org/abs/2307.16402

Semiconducting transport in Pb10-xCux(PO4)6O sintered from Pb2SO5 and Cu3PLi Liu, Ziang Meng, Xiaoning Wang, Hongyu Chen, Zhiyuan Duan, Xiaorong Zhou, Han Yan, Peixin Qin, Zhiqi Liu https://arxiv.org/abs/2307.16802