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LK-99: Team of Southeast University observed zero resistance below 110 K

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Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#101

Post by consilient »

jacquesm wrote: post #78
mjh2539 wrote: post #68

Earlier quoted context omitted.

That doesn't follow at all. Lead and copper aren't exclusive to South Korea. The authors get prestige and the owners of whatever patents are granted get some money.

Of course they aren't. But patent owners get to set the terms under which their patents are licensed. It's not like the record business where there is a fixed deal and if you use someone's lyrics you know up front what it is going to cost you. Someone might not even want to do business with you at all...

> But patent owners get to set the terms under which their patents are licensed

To private entities, sure. The US government can and will force you to grant them a license if necessary.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#102

Post by sema2 »

bigmattystyles wrote: post #75

Novice question - does a material behaving as a superconductor occur all the sudden like a step function if resistance is plotted against temp and pressure - or does it ease into super conductor behavior? (edit) Also is it resistance (aka if I remember my EE degree correctly), DC only or also impedance where frequency also matters?

I do find that interesting... I found a graph of another HTSC's (YBCO) resistance vs temperature [1], and the function is much more discontinuous looking than the one shown in the article. That would lead me (someone not at all trained in the physics of superconductors) to believe that perhaps the purity of the sample is a factor here, with different parts of the sample having different critical temperatures, gradually decreasing resistance until an inflection point is reached at 110K.

1. https://www.researchgate.net/figure/The-electrical-resistivi...

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#103

Post by hatsunearu »

The Fig 3a)b) graphs are not showing superconductivity. That just looks like the resistance dips below the ~1e-5 mark and goes goes deep into the noise. That just looks like a normal conductor that has a positive temperature coefficient.

edit: to add speculation, I think they made something that's not quite LK-99, and it's behaving like a normal conductor with no superconductance.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#104

Post by barbegal »

This doesn't look superconducting at all to me, simply the sample is very small and below 110K the resistance of the sample is too small to be measured by their measurement equipment. I'm happy to be proved wrong but there should be a steeper transition at the critical temperature.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#105

Post by [deleted] »

sema2 wrote: post #102
bigmattystyles wrote: post #75

Novice question - does a material behaving as a superconductor occur all the sudden like a step function if resistance is plotted against temp and pressure - or does it ease into super conductor behavior? (edit) Also is it resistance (aka if I remember my EE degree correctly), DC only or also impedance where frequency also matters?

I do find that interesting... I found a graph of another HTSC's (YBCO) resistance vs temperature [1], and the function is much more discontinuous looking than the one shown in the article. That would lead me (someone not at all trained in the physics of superconductors) to believe that perhaps the purity of the sample is a factor here, with different parts of the sample having different critical temperatures, gradual…

[deleted]

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#106

Post by ReptileMan »

chaimanmeow wrote: post #7

credibility of LK99 claims is very very high. What are the medium term practical implications for all these potential applications?

0 applications out of the door but huge leap for material science. And some of the best and brightest people will look for something deep there.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#107

Post by borkt »

jacquesm wrote: post #93
borkt wrote: post #81

Earlier quoted context omitted.

Observed effects which have been given a name != a single universal truth. Just because we have experimental evidence of effects and theoretical explanations for their occurrence prove we actually have defined the underlying phenomenon's which produce the observed effect accurately. The reason we experiment isn't to prove our theories are correct so much as it is to probe where they break down so we can further refin…

Yes, that's true, but that would require a shift in our understanding of physics and everything about this saga so far has not done that. And that in part is a reason why people take this serious: it is believable. New physics would raise the bar considerably. So for now I'm on the measuring error, impurity or process issue side of that without committing to which team I think has the problematic side.

The fact that our existing computational models are in agreement with the experimental behavior leads me to believe there is no new physics involved here. That being said this raises the question as to whether this class of material is known and characterized within our national research labs but has been kept classified, and if it was unknown it raises the question of why experimentation is what discovered it and why weren't we able to harness the computational model to identify it theoretically and develop a method to produce it practically prior to this. My money says there are people in this world who have long been aware of this, and its either already in use in a classified manner or it's interesting but there are other materials which are more practical in all use cases.

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#108

Post by uyhgr »

Workaccount2 wrote: post #74
gchadwick wrote: post #14

Certainly no expert here but if you take the original video and replications at face value it does exhibit strong diamagnetism at room temperature. Superconductors are diamagnetic due to the Meissner effect at their superconducting temperature. This would mean LK99 is a superconductor at low temperature and separately be strongly diamagnetic at room temperature (no Meissner effect if it's not super conducting). Would…

I have seen it posted that diamagnetic materials require multiple magnets stuck together to create field "pockets" (?) for the material to rest in. The few videos of lk99 show it reacting to a singular magnet. A property of superconductors that apparently diamagnetic materials don't have.

The term is “flux pinning”, and it only applies to the “quantum lock” effect. That is the specifically static hovering effect.

The diamagnetism, importantly this means repulsion of both poles simultaneously and equally (this is how you can have these magnets spin, a regular magnet repels same poles and attracts opposites, diamagnets repel both poles), is simply a characteristic of the superconductor, but it alone would just repel the object off.

Here is a timestamped link to NileRed’s YBCO video that visually describes the flux pinning:

https://m.youtube.com/watch?v=RS7gyZJg5nc&t=1887

And here’s a timestamped link to Ben Krasnow’s Applied Science YBCO video where he shows a close up of the crystal’s cross section that shows the imperfections that allow the magnetic field through for the pinning effect:

https://m.youtube.com/watch?v=sLFaa6RPJIU&t=75

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#109

Post by jacquesm »

consilient wrote: post #101
jacquesm wrote: post #78

Earlier quoted context omitted.

Of course they aren't. But patent owners get to set the terms under which their patents are licensed. It's not like the record business where there is a fixed deal and if you use someone's lyrics you know up front what it is going to cost you. Someone might not even want to do business with you at all...

> But patent owners get to set the terms under which their patents are licensed To private entities, sure. The US government can and will force you to grant them a license if necessary.

Yes, except that's the US government and the inventors here are in South Korea. I don't think the US would get away with declaring 'eminent domain' over something invented in a different country. They could choose to simply not honor the patent but that will open a massive can of worms, especially because a lot of this stuff depends on reciprocity: if your government doesn't honor our key patents, why should we do the reverse?

Re: LK-99: Team of Southeast University observed zero resistance below 110 K

#110

Post by barbegal »

hatsunearu wrote: post #103

The Fig 3a)b) graphs are not showing superconductivity. That just looks like the resistance dips below the ~1e-5 mark and goes goes deep into the noise. That just looks like a normal conductor that has a positive temperature coefficient. edit: to add speculation, I think they made something that's not quite LK-99, and it's behaving like a normal conductor with no superconductance.

That would be my interpretation too. Usually you get a stronger transition to 0 at the critical temperature but I can't see this (although it could be hidden under the noise)
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