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| South Korean Scientists Claim Ambient Temp. Superconductivity |
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| gnuarm:
--- Quote from: HuronKing on July 27, 2023, 08:18:25 pm --- --- Quote from: gnuarm on July 27, 2023, 05:35:59 pm ---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. --- End quote --- 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. --- End quote --- I'm sure that's true for various MRI machines. But superconductors exist at temperatures well above 60 °K. |
| HuronKing:
--- Quote from: gnuarm on July 27, 2023, 08:35:36 pm --- --- Quote from: HuronKing on July 27, 2023, 08:18:25 pm --- --- Quote from: gnuarm on July 27, 2023, 05:35:59 pm ---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. --- End quote --- 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. --- End quote --- I'm sure that's true for various MRI machines. But superconductors exist at temperatures well above 60 °K. --- End quote --- 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! ;D |
| 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:
--- Quote from: SiliconWizard on July 27, 2023, 09:35:38 pm ---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. --- End quote --- I did read it - some of the terminology and referenced theorems were unfamiliar to me but the key statement appears to be this: --- Quote ---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. --- End quote --- 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. :-// |
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