South Korean Scientists Claim Ambient Temp. Superconductivity

[HuronKing]

Not peer reviewed - published on arXiv:
https://arxiv.org/ftp/arxiv/papers/2307/2307.12008.pdf

[Gyro]

There's an ongoing discussion. Whether it deserves to remain in the Dodgy Technology section remains to be seen...

https://www.eevblog.com/forum/dodgy-technology/room-temperature-superconductor-386518/

[Infraviolet]

If it is a real result, very impressive and perhaps world changingly useful. Most of the recent cotnroversies about high temp superconductors have been amount materials working at room temperature, but only under incredible pressures between the points of diamond anvils, unlike those this discovery, if it can be replicated, looks ready for much quicker practical deployment.

[HuronKing]

There's an ongoing discussion. Whether it deserves to remain in the Dodgy Technology section remains to be seen...

https://www.eevblog.com/forum/dodgy-technology/room-temperature-superconductor-386518/

Thanks - I never read that subforum so I was unaware it was already being discussed. Apologies if a mod needs to lock this one up!

[KE5FX]

Hopefully the thread in Dodgy Technology can be the one that gets closed.  But I wouldn't bet on it...

[Bud]

It must be a bit hot in Korea, if 127 C is room temperature to them.

[gnuarm]

It must be a bit hot in Korea, if 127 C is room temperature to them.

LOL  That's the max temperature.  It is superconducting at temperatures below that.  The impressive bit, is the lack of need for high pressures.

However, there's still a lot of other requirements for it to be useful.  It has to have physical properties that allow it to be formed into useful shapes and have tolerance to shock, vibration, etc. 

[HuronKing]

It must be a bit hot in Korea, if 127 C is room temperature to them.

LOL  That's the max temperature.  It is superconducting at temperatures below that.  The impressive bit, is the lack of need for high pressures.

However, there's still a lot of other requirements for it to be useful.  It has to have physical properties that allow it to be formed into useful shapes and have tolerance to shock, vibration, etc.

Yes to the needing to be useful shapes but I think tolerances for shock/vibration are less critical for some of the most immediate applications. MRI machines already have fairly low tolerances for those things and that's where ambient superconductors would be a wonderful thing to have. No more helium cooling requirements - oh how great it would be for MRIs to just be something you can do without it being a big expensive deal.

[gnuarm]

I thought we already had superconductors at liquid nitrogen temperatures?  That's much easier to come by than liquid helium.  You can easily make liquid nitrogen in any facility.

[HuronKing]

I thought we already had superconductors at liquid nitrogen temperatures?  That's much easier to come by than liquid helium.  You can easily make liquid nitrogen in any facility.

Liquid nitrogen can only get down to 60K. That's used for external cooling. The internal MRI magnet materials need to get down to 4K for superconductivity:
https://mriquestions.com/superconductive-design.html

The cooling apparatus are the most expensive and difficult part of MRI machines. Eliminating the need for complex liquid helium containment would make MRI machines far cheaper and mobile.

[gnuarm]

I thought we already had superconductors at liquid nitrogen temperatures?  That's much easier to come by than liquid helium.  You can easily make liquid nitrogen in any facility.

Liquid nitrogen can only get down to 60K. That's used for external cooling. The internal MRI magnet materials need to get down to 4K for superconductivity:
https://mriquestions.com/superconductive-design.html

The cooling apparatus are the most expensive and difficult part of MRI machines. Eliminating the need for complex liquid helium containment would make MRI machines far cheaper and mobile.

I'm sure that's true for various MRI machines.  But superconductors exist at temperatures well above 60 °K.

[HuronKing]

I thought we already had superconductors at liquid nitrogen temperatures?  That's much easier to come by than liquid helium.  You can easily make liquid nitrogen in any facility.

Liquid nitrogen can only get down to 60K. That's used for external cooling. The internal MRI magnet materials need to get down to 4K for superconductivity:
https://mriquestions.com/superconductive-design.html

The cooling apparatus are the most expensive and difficult part of MRI machines. Eliminating the need for complex liquid helium containment would make MRI machines far cheaper and mobile.

I'm sure that's true for various MRI machines.  But superconductors exist at temperatures well above 60 °K.

Yes but none of those are suitable for applications where we need to use liquid helium (MRIs being the most common case) which is what I thought you were referring to (since that's the example I was pointing at).

Some stuff can superconduct with liquid nitrogen but its still hardly ambient temp! 

[TimFox]

For a result as important as this, I would wait for an article in a peer-reviewed journal before applauding.

[SiliconWizard]

Has anyone read the article in full? Not my area of expertise, but still a number of key statements in it smell like nice BS.
Also waiting for specialists to review it.

[HuronKing]

Has anyone read the article in full? Not my area of expertise, but still a number of key statements in it smell like nice BS.
Also waiting for specialists to review it.

I did read it - some of the terminology and referenced theorems were unfamiliar to me but the key statement appears to be this:

Consequently, why does LK-99 exhibit superconductivity at room temperature and ambient
pressure? This is because the stress generated by the Cu2+ replacement of Pb(2)2+ ion was not
relieved due to the structural uniqueness of LK-99 and at the same time was appropriately
transferred to the interface of the cylindrical column. In other words, the Pb(1) atoms in the
cylindrical column interface of LK-99 occupy a structurally limited space. These atoms are entirely
affected by the stress and strain generated by Cu2+ ions. Therefore, SQWs can be generated in the
interface by an appropriate amount of distortion(57) at room temperature and ambient pressure
without a relaxation. From this point of view, the stress due to volume contraction by temperature
and pressure is relieved and disappeared in CuO- and Fe-based superconductor systems because
the relaxation process cannot be limited due to the structural freedom. Therefore, they need an
appropriate temperature or pressure to limit the structural freedom and to achieve the SQW
generation.

This whole section seems like a wholly inadequate theoretical description of what is happening. The paper doesn't really explain why this would cause magnetic fields to be expelled from the structure of the atoms which is a necessary condition for superconductivity. It may be that some things are lost in translation but it doesn't seem like they fully understand why this happened - assuming their data is correct!

I also just noticed some of their diagrams use comic-sans font. 

Maybe Dodgy Tech is where this belongs. 

[TimFox]

MRI superconductors need to work at high current and high magnetic field, not just superconduct at a useful temperature.

[gnuarm]

I thought we already had superconductors at liquid nitrogen temperatures?  That's much easier to come by than liquid helium.  You can easily make liquid nitrogen in any facility.

Liquid nitrogen can only get down to 60K. That's used for external cooling. The internal MRI magnet materials need to get down to 4K for superconductivity:
https://mriquestions.com/superconductive-design.html

The cooling apparatus are the most expensive and difficult part of MRI machines. Eliminating the need for complex liquid helium containment would make MRI machines far cheaper and mobile.

I'm sure that's true for various MRI machines.  But superconductors exist at temperatures well above 60 °K.

Yes but none of those are suitable for applications where we need to use liquid helium (MRIs being the most common case) which is what I thought you were referring to (since that's the example I was pointing at).

Some stuff can superconduct with liquid nitrogen but its still hardly ambient temp! 

Which is what I said, no? 

I thought we already had superconductors at liquid nitrogen temperatures?