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Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

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Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#201

Post by adrian_b »

s0rce wrote: post #90
tomohelix wrote: post #30

Summary of events so far: The claim: Room temp (~300K) superconductor exists and we got it! The replication attempts: The production method is so poorly documented only a fraction of the samples being made shows any interesting properties. And among those interesting ones, results varies. Very few, if any, attempt actually completely shows the entire spectrum of properties and behaviors of a true superconductor at ro…

Most papers are so bad its nearly impossible to replicate the synthesis.

Not this one, which has a very detailed description of the synthesis, including what has worked and what has failed.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#202

Post by yreg »

generalizations wrote: post #121
swagmoney1606 wrote: post #98

Earlier quoted context omitted.

We'll probably know for sure within the month!

Somewhat disappointed the russian twitter anon isn't included, since they seem to have made the first replication attempt that might have panned out.

Ah this again. No offense to you, but yes, the obnoxious anonymous Russian troll who's only proof is a photo of a spec of dust (glued?) in a syringe, who refuses to take a video, who says she didnt follow the paper beause she immediately invented a better way to make a different room temp superconductor, who says she doesnt care about superconductors and who keeps tweeting bizzare USSR propaganda?

I wonder why she's not included in the Wikipedia article. /s

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#203

Post by _ph_ »

reacharavindh wrote: post #200
tomohelix wrote: post #30

Summary of events so far: The claim: Room temp (~300K) superconductor exists and we got it! The replication attempts: The production method is so poorly documented only a fraction of the samples being made shows any interesting properties. And among those interesting ones, results varies. Very few, if any, attempt actually completely shows the entire spectrum of properties and behaviors of a true superconductor at ro…

With my conspiracy theory hat on, perhaps the authors were encouraged/coerced to not release proper documentation to reproduce the recipe entirely by [their bosses, state agencies etc.] If the claims are true, then the implications to defense, weaponry and such are very high, and the C |N |D* agencies like to not lose their cards in the game.. /conspiracy Or Real science is just darned difficult, and the scientists a…

Right. From my own experience, growing crystals is close to alchemy. Of course we know exactly how to do it, yet, it takes a lot of skill to grow a lot of substances. There are a lot of detaills to the process which are difficult to capture in documentation, even if the best faith attempts are made. Add to that any variation in the machinery used. As a consequence, it is quite common in crytallography that there is a single source for certain crytals. At least in an initial phase. If a substance becomes reasonably popular, eventually more people manage to produce quality crystals.

So I would expect eventually good samples to turn up elsewhere as many groups are working on this, but it can take a lot of time. Especially as no one knows what exactly was different about the Korean samples.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#204

Post by gabesullice »

mrandish wrote: post #19

For comparison, per this Wikipedia page ( https://en.wikipedia.org/wiki/High-temperature_superconducti... ) currently, the highest temperature, ambient pressure superconductor is around 138 K (−135 °C). I'm no expert but based on my limited understanding, this result (if confirmed) while far from room temperature would still make LK99 a pretty interesting discovery in the SC world. And once a new SC like this is vali…

Agreed. Looking at the timeline on the Wikipedia page, a new 100K ambient pressure SC material is nothing to scoff at.

It means LK99 is about as good as the other materials, at minimum. However, its chemical composition is different than any of the other materials on the chart (i.e. it is lead based). That probably means there's lots to learn and new phenomena to be understood and optimized.

Furthermore, if this lab could achieve these results in a matter of weeks, perhaps labs with more exotic equipment and dedication will be able to get better results, raising the bar even higher.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#205

Post by awwkaw »

ayakang31415 wrote: post #34
keyle wrote: post #26

> In conclusion, we successfully synthesized the compound Pb10-xCux(PO4)6O, and observed the zero resistance above 100 K. However, the Meissner effect has not been observed yet in our samples, which suggests that the superconducting volume is relatively low. In conclusion, ... nothing?

It's definitely something, rather big something, to observe zero resistance above 100k

Not compared to the claim of zero restance up to 400 K.

But with how difficult the samples production seems to be, maybe we will get 400 K superconductors still

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#206

Post by amelius »

segfaultbuserr wrote: post #21
lifthrasiir wrote: post #8

I'm very much conservative about this paper because while the graph in Fig. 3a says $T_c^{zero}$ being 110 K, the "zero" resistance is actually only 1e-5 Ω (!) and even if the sample is possibly superconducting its critical temperature would be much lower than 110 K anyway. I'm aware of the difficulty in obtaining larger samples, but the label in that graph is really misleading regardless.

The resistance curve stopped at 1e-5 Ω because it has nearly reached the resolution limit of their instrument. Using 4-wire Kelvin sensing, the measurement current was 1 mA, the voltage read-out across the material was around 1 to 10 nanovolts - this is around the scale that some of the world's best general-purpose voltmeters can measure down to. The authors assumed that the negligible voltage drop, combined with the…

Curious, why didn't they use a larger current for the measurement?

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#207

Post by IsTom »

46Bit wrote: post #76
jcranmer wrote: post #47

Looking at the key temperature-resistivity graphs, this feels like the data doesn't support the conclusion that there's a superconductor here. The temperature-resistivity graphs of superconductors I've seen all have a fairly steep cutoff--a sharp, vertical line at critical temperature. The log-scale here complicates my intuition, but what I see is a gradual transition into noise range. Also, the graphs I've seen have…

https://nitter.net/condensed_the/status/1686895266329174016 claims a linear representation of the same data. Still no convincing discontinuity visible.

Makes the dip around 250K even more visible.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#208

Post by sashank_1509 »

generalizations wrote: post #121
swagmoney1606 wrote: post #98

Earlier quoted context omitted.

We'll probably know for sure within the month!

Somewhat disappointed the russian twitter anon isn't included, since they seem to have made the first replication attempt that might have panned out.

Anon is fine, I’m inclined to promote anons who do credible replications. Russian anon is not one of them, she really should take a video at the very least, even then her speck is so small until she released detailed measurements one can’t in good faith trust her. I won’t be surprised if at the end of all this, she just claims she was trolling in good fun and we’re the fools for taking anything she says seriously.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#209

Post by DoingIsLearning »

coderenegade wrote: post #138
dgoldstein0 wrote: post #48

Earlier quoted context omitted.

The biggest near future tech for superconductors: fusion power. One huge area of exploration for fusion power is tokamok reactor design, which requires a very strong magnetic field to confine plasma within a round shape - typically a torus, though I think I read of one spherical shell. I suppose these don't necessarily need room temperature super conductors, but cheaper and easier to manufacture superconducting mater…

I think energy storage, motors / accelerators and weapons would come first. A superconducting linear motor would probably also make for a great cannon.

If we are talking DARPA money, I think working out how to build IC sensors using this stuff would be much quicker to reach manufacturing then a large scale motor winding.

I am sure defense folks would have a field day with new sensors with virtually no thermal noise.

Re: Observation of zero resistance above 100 K in Pb₁₀₋ₓCuₓ(PO₄)₆O

#210

Post by DrBazza »

jcranmer wrote: post #74
tomohelix wrote: post #30

Summary of events so far: The claim: Room temp (~300K) superconductor exists and we got it! The replication attempts: The production method is so poorly documented only a fraction of the samples being made shows any interesting properties. And among those interesting ones, results varies. Very few, if any, attempt actually completely shows the entire spectrum of properties and behaviors of a true superconductor at ro…

> Worst case scenario, we got another class of high temp (warmer than liquid nitrogen but cold enough that applications are limited) superconductor but nothing revolutionary since at this point, it is pretty conclusive that there is something interesting with LK-99. I don't think that's the worst case scenario. The worst case scenario is that there is actually nothing interesting with LK-99, and everything we've seen…

> I'm actually surprised by the sheer lack of people commenting in the more-or-less-perma-LK-99 threads who show skepticism of the results.

HN is supposed to have a high signal-to-noise for comments. I'm skeptical about this. I think it's the modern Pons + Fleishmann, but I won't post that on every thread because it contributes nothing. There's more insightful, and interesting comments about chemistry than anything I can write that would add to the discussion.

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