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

arxiv.org

71–80 of 389 posts

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

#71

Earlier quoted context omitted.

MRI machines work using superconducting magnets as does the LHC. So you better believe it buddy.

Why do MRIs need zero resistance vs incredibly low resistance?

Because the resistance is the limiting factor in how strong a magnetic field can be made in a given volume using the conducting material.

Copper across an area of 1 cm ^2 does about 300A, compare with https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8047038/ for what some superconductors can do.

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

#72

A 110k superconductor would not be revolutionary since we already have some in that vicinity.

Is my understanding correct that 100k at ambient pressure is pretty special on its own?

YBCO and BSCCO are superconductors around 100K at ambient pressure. Unfortunately their brittleness limits their practical use. Maybe LK-99 will have better mechanical properties.

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

#73

Question for the cognoscenti: supposing that LK-99 superconducts with T_c = 110 K, how significant a discovery would this be? I.e., does it establish a brand new class of high-T superconductors, or is it merely one unremarkable member of a known class? Further, does it offer advantages over other high-T superconductors such as ease of fabrication or cost?

It's a brand new class.

The material cost is lower than most superconductors - it's lead and copper - but no one has any idea on fabrication, yield size, etc., now, so no good answers there.

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

#74

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 that suggests otherwise is experimenter bias heaped on top of experimental error. 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.

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

#75

A 110k superconductor would not be revolutionary since we already have some in that vicinity.

This is not about 110K, this is about trying to verify the results related to LK-99. The LK-99 that is room temp superconductive seems quite difficult to produce at this early stage. But these researchers were able to produce their not-as-good version of LK-99 and at least verify very close to superconductivity at 110K. This makes the LK-99 room temp superconductivity claims that much more plausible.

Exactly. There are too many unknowns to draw any kind of real conclusions, but everything so far still supports a position of cautious optimism.

What we know is that LK-99 looks pretty interesting. Is it a room-temperature superconductor? Maybe!

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

#76

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.

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

#77

Earlier quoted context omitted.

Zero loss diodes seem pretty useful.

Especially if the material happens to have photo electric properties too...

...and gain, at an incredibly fast slew rate!

I mean, we're laundry list fantasizing, right? [shrug emoji]

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

#78
post #77

Earlier quoted context omitted.

Especially if the material happens to have photo electric properties too...

...and gain, at an incredibly fast slew rate! I mean, we're laundry list fantasizing, right? [shrug emoji]

Well, yes. But both Silicon, Selenium and Germanium as well as all metals that are shiny are photoelectric. If this thing can form diodes that open a potential path to very high efficiency solar cells. It wouldn't be the first either:

https://www.nature.com/articles/srep11504

"Origin of photovoltaic effect in superconducting YBa2Cu3O6.96 ceramics"

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

#79

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…

Agreed. Even the 100K zero-resistance claim isn't holding up to scrutiny https://nitter.net/condensed_the/status/1686895266329174016 https://nitter.net/condensed_the/status/1686901855358427136 https://nitter.net/condensed_the/status/1686832552252784641

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

#80

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…

You're right that this is the worst case scenario, but each interesting replication or semi-replication, even sloppy replication, or theoretical model erodes at that.

Being perma-skeptic is as bad as being a perma-fanboy

Anyways your memory is really short. Don't you remember how when it first came out (not even a week ago) everyone was hollering that it was fake?

Inb4 "extraordinary claims...": there is no fundamental reason for superconductivity in general to be impossible at RT.

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