Superconductor Pb$_{10-x}$Cu$_x$(PO$_4$)$_{6O}$ showing levitation at room temperature and atmospheric pressure and mechanism

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Superconductor Pb$_{10-x}$Cu$_x$(PO$_4$)$_{6O}$ showing levitation at room temperature and atmospheric pressure and mechanism

Authors

Sukbae Lee, Jihoon Kim, Hyun-Tak Kim, Sungyeon Im, SooMin An, Keun Ho Auh

Abstract

A material called LK-99, a modified-lead apatite crystal structure with the composition Pb$_{10-x}$Cu$_x$(PO$_4$)$_{6O}$ ($0.9<x<1.1$), has been synthesized using the solid-state method. The material exhibits the Ohmic metal characteristic of Pb(6s1) above its superconducting critical temperature, $T_c$, and the levitation phenomenon as Meissner effect of a superconductor at room temperature and atmospheric pressure below $T_c$. A LK-99 sample shows $T_c$ above 126.85$^\circ$C (400 K). We analyze that the possibility of room-temperature superconductivity in this material is attributed to two factors: the first being the volume contraction resulting from an insulator-metal transition achieved by substituting Pb with Cu, and the second being on-site repulsive Coulomb interaction enhanced by the structural deformation in the one-dimensional(D) chain (Pb2-O$_{1/2}$-Pb2 along the c-axis) structure owing to superconducting condensation at $T_c$. The mechanism of the room-temperature $T_c$ is discussed by 1-D BR-BCS theory.

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50 comments

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Steinn

this is interesting, looking forward to independent lab confirmation

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xirtam-esrevni

1. Is LK-99 a cuprate given Pb(10-x)-Cu(x)(6O) (0.9< x < 1.1)? I assume this is why BR-BCS theory is used to discuss. But aren't there known issues with BR-BCS?
  • The on-site Coulomb interaction would need to be very strong and infinite. However, the on-site Coulomb interaction is always finite in reality.
  • The disorder in real materials would likely prevent the formation of Cooper pairs. 
  •  Cooper pair formation mechanism is absent in these theories.

2. Whats the explanation for the partial levitation.

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scicastboard

Levitation is obviously a very strong argument, but not bullet proof. It's known to exist for example in non-superconducting graphite (@ 6'40''): 
https://www.youtube.com/watch?v=TlD12QObooc

There are many groups trying to reproduce these data. Perhaps, the fastest way would be for the authors of this work to send samples around to others - that would relieve concerns. 

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galactic

Can you mention any specific groups working on replicating these results?

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mattgentz03

@galactic the paper shows that creating the LK-99 metal took 72 hours, so I don't think we'll know for certain until the end of the month. On the plus side, though, it looks like lots of labs can do this, since it's frankly ridiculously cheap. An experienced metallurgist(?) could probably make this for under $250. 

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Erik

The graphite only levitated cause it was in the groove between multiple magnets, that were layin next to each other. Seeing that here is only 1 magnet and he could freely move it around on it, so it wasnt multiple hidden magnets, i dont see this as a possibility.

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Sea

I hope it's true

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Fleey

Thats amazing!

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ccnujrzero

It's hard to believe,but not hard to verify.If ture,it would be a scientific revolution.

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grockerm

wait some time

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bigees

amazing

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noobww73

crazy

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mahuatenshishabi

cannot believe it

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Some earthling

 Me neither.  The video is indistinguishable from playing around with a couple permanent magnets. 

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cyyooooo00

In the annals of history, a monumental event unfurled, igniting the spark that set ablaze humanity's technological prowess, and thus, our journey commenced.

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davidlam-hk-ak47

Not sure if the rather simple production method may be totally replicable. Though it seems it can provide a general direction towards the ultimate goal of room temperature room pressure superconductors?

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agatct

I wish it would be true and contribute to a bright future of humanity.

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agatct

 I wish it would be true and contribute to a bright future of humanity. 

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scicastboard

Dear ScienceCast Users,

We are delighted to welcome you to our website and are thrilled to witness such keen interest in the potentially groundbreaking paper by Dr. Kim and collaborators.

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lentonen-henri

Greetings from Finland! What a great finding, we can def use this in our AI powered agriculture reform microalgae facility

bonecotech.wordpress.com

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Adrian

I hope this is true, and if it is, it will be a great leap forward for human civilization.

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Peter

Hi, can you turn the magnet around and demonstrate flux-pinning? (i.e. the sample hanging from the magnet)

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sky

期待能够看见何教授吃上答辩!

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fortheaffairs

何教授,您吃了吗

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mstellaris

何教授说他不是赌的这种材料,哈哈

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z-z

有直播记得叫上大伙

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iccas1956

吃了没? 如吃

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gu15113862778

何餐已發表免責聲明

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fortheaffairs

Wow,  another technology revolution  if it is practicable

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fawzicui

如果是真的,这必将载入史册。先火钳刘明

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ZhiwenYyn

起猛了,看见手搓室温常压超导了。

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zhengqishan23

如果是真的,吃就吃吧!

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zhengqishan23

But isn't this levitation really caused by the material after it has been magnetized?

In the process of using neodymium magnets and magnet crumbs, we can observe the suspended state of magnet crumbs usually.


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iccas1956

如吃

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Asil

AMAZING

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Some earthling

The video does not show levitation.  One edge is supported on the permanent magnet. One could achieve the same thing with a material simply having a magnetic dipole strong enough to lift it, but not strong enough to flip it over.  If he flipped the sample over and it was still lifted similarly that would be impressive. This is not impressive, and seems deceptive to me.

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Some earthling

On the other hand, it does seem unlikely that all these researchers would be tossing their careers out the window just by hyping an easily disprovable scam though, so I am optimistic in spite of this very weak "demonstration" video.

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n-chub

Well, did you notice the sample was 'partially levitating ' on 2 different levels? When the person tossed it with a pen it changed its angle but still did not level out. Permanent magnets imho would find a balance of forces position as the magnetic field density decrease with distance, so there should be a point of force balance, right? Doesn't it suggest a different phenomena from just two magnrtic dipoles? 

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Some earthling

I disagree with your conclusion, because when the sample is pushed it ends up a different location on the magnet  further from center, so the field will have a different angle at the new location, which would cause exactly what is observed with a magnetic dipole material (like a chip off a weak magnet) as the dipole aligns with the field as much as possible against the friction of the points of contact and the weight of the sample.  All they had to do was flip it over and if it still didn't lay flat that would be a good demonstration of the Meissner effect. What is in the video could maybe be due to Meissner effect, but is entirely indistinguishable from playing around with a couple permanent magnets.  

Also, if you look closely there is what appears to be a tiny chip of sample material stuck to the edge of the magnet, as if it is attracted to the magnet magnetically. If that is a chip from the sample, it sticking there is perhaps counter to the stated conclusion. I'm not sure how a superconductor would behave on a surface that is parallel to the magnetic field (the edge of a magnet) but it would need to be magnetic to some degree to stick there like that.  

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Rhyothemis

Congratulations!

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jhirsch

"Give me a foothold and I will turn the Earth"
https://jorge.physics.ucsd.edu/roomtlevitation.mov

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scicastboard

Professor Hirsch -- It's great to see you chiming in on the subject, where you're clearly an expert with original views. We noticed that the authors cited your theory of hole superconductivity. We would appreciate your extended thoughts on this experiment.

One concern, which was pointed out by some is illustrated in this plot.
FiniteR.png 93.5 KB

Answer
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bgrinstein

https://nationalmaglab.org/magnet-academy/watch-play/science-demos/eddy-currents-in-action/

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peterkimberlin

Now I can say we are living in 21st century.

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dirvine

a) Flip the sample. To eliminate magnetic dipole effect. 
b) Cut the sample in two to give us a fully levitating sample.
c) Why was this not done before the video?
Still leaves the possibility of an extreme diamagnetic material like graphite.

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gd19932153065

不是,哥们你来真的啊

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henninglevoss

Need to show that the incomplete levitation is not just magnetic repulsion of a potentially inhomogeneous magnetic material 

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henninglevoss

Or, as someone else already posted, just eddy currents. Whatever it is, it might not be Meissner levitation 

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deanmorris010

If a sample was made smaller into a spherical or cylindrical shape, would it then exhibit properties to fully levitate and spin in the magnetic field?

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exeandino

Hace unos días desbloquee este conocimiento, aguardo noticias y quizás ya podemos vender patinetas voladoras, que más?

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