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I found Thunderf00t's video on LK-99 to be funny because he pointed out something no one else did: In almost all applications of superconductors, they don't use

I found Thunderf00t's video on LK-99 to be funny because he pointed out something no one else did: In almost all applications of superconductors, they don't use high-temperature ones for one simple reason: Material properties. Most high-temp superconductors (including LK-99, he was assuming it was one, since he's not qualified to say one way or the other) are a ceramic. The ones that see use in the LHC, for instance, aren't. They're metallic, so you can form them into the shape you need without having to manufacture it in that shape to begin with, since you'd need another superconductor to join pieces like glue, which we don't have. That alone doomed LK-99 to the department of "cool, but not super useful", since most of the really interesting uses were for large things, not small ones.

reportingsjr 3y ago
The current generation of mass manufactured high temperature superconducting tape is based on YBCO, which is a crystalline material (presumably what is meant here when saying ceramic). So the argument that superconductors need to be metallic/malleable to be useful doesn't really make a lot of sense.
- kergonath 3y ago
  > presumably what is meant here when saying ceramic Probably not. Being crystalline and being a ceramic are completely unrelated. Standard superconductors like niobium-tin and niobium-titanium are crystalline metals (intermetallic alloys). The vast majority of metals are crystalline, to the point that when a company tried to make a metallic glass a couple of years ago (under the name Liquid Metal), it made quite a bit of noise.
  - willis936 3y ago
    That's fine but YBCO is a crystalline ceramic.
    - kergonath 3y ago
      Indeed. With a perovskite-related structure.
  - jacquesm 3y ago
    > to the point that when a company tried to make a metallic glass a couple of years ago (under the name Liquid Metal), it made quite a bit of noise. https://en.wikipedia.org/wiki/Liquidmetal https://en.wikipedia.org/wiki/Liquidmetal
- downWidOutaFite 3y ago
  YBCO isn't really used for anything. MRI machines use metallic NbTi even though it requires liquid helium because YBCO is too brittle and can't handle large currents.
floxy 3y ago
The existing high temperature superconductors in production are also ceramics. They just deposit thin layers on another substrate and then you get flexible tapes. When you hear "second generation" HTS tapes, that is what people are referring to. AMSC and SuperPower crank it out by the mile. https://duckduckgo.com/?t=ffab&q=superconducting+tape&iax=images&ia=images https://duckduckgo.com/?t=ffab&q=superconducting+tape&iax=im...
kergonath 3y ago
> Most high-temp superconductors (including LK-99, he was assuming it was one, since he's not qualified to say one way or the other) are a ceramic. The ones that see use in the LHC, for instance, aren't. Aren’t the LHC magnets niobium-titanium? Those aren’t high temperature superconductors. Though it is indeed a metal under any definition. The rule of thumb is that high-temperature superconductors can be cooled by liquid nitrogen alone. This is not the case of the LHC magnets, which also have a liquid helium cooling loop. > They're metallic, so you can form them into the shape you need without having to manufacture it in that shape to begin with, since you'd need another superconductor to join pieces like glue, which we don't have. The term “metallic” is unhelpful because often in material science it just means an electronic conductor (a material with a non-zero density of states at the Fermi level). Under that definition, some ceramics are metallic, and the opposite of “metallic” is “insulator”, or sometimes “semi-conductor”. YBCO, which is probably the most used high-temperature superconductor, is an oxyde, so a ceramic, but still an electronic (super)conductor, so metallic. The fact that it’s an oxyde does not prevent its use, notably in spherical tokamaks. So I don’t know the person you’re referencing but their background work on the subject seems less than adequate, from what you say.
- putnambr 3y ago
  Did you skip over "In almost all applications of superconductors, they don't use high-temperature ones for one simple reason: Material properties." They're saying that LHC does not use a ceramic, and therefore high-temperature, superconductor; instead they use metallic (cooled) superconductors because they can be molded.
  - kergonath 3y ago
    The sentence still does not make sense because the superconductors in the LHC (though, rereading it a couple of times it is somewhat ambiguous) are not high temperature by any definition. Also, again, ceramic high-temperature superconductors are metallic, or they would not be conductors. “Ceramic” and “metallic” are not mutually exclusive in material sciences. There are lots of reasons to use more classical superconductors in the LHC, just as in ITER. Some are design and engineering issues, as you mention. Another one is that the tapes we use for YBCO were not a practical thing when the LHC was designed. But now they are (though they haven’t been used in such a large scale) and you can bet that they’ll jump at any opportunity to get rid of the helium loop and take advantage of the stronger magnetic fields you can get with YBCO.
seiferteric 3y ago
I thought it was a poor point. The paper proposed a new mechanism for the superconductivity, which would have been a bigger deal than this specific formulation (lk-99). If it were true, it would be a new class of superconductors which I would think this would lead to development of new formulations that perhaps had better properties. Plus as others have said, superconductor material can and is deposited on tapes (see ReBCO) to make it usable.
- EvgeniyZh 3y ago
  They didn't propose new class of superconductors. They conjectured that LK99 follows some 25-year-old theory from a paper written in Korean. Leaving alone the fact that the theory doesn't make much sense to me (at least the parts I managed to understand), there was no evidence in the LK-99 paper that this mechanism is indeed what makes LK99 superconductive (or more precisely that it is present in LK99).
rowanG077 3y ago
The problem, which is often the case with Thunderf00t, is that he is missing the forest for the trees. No one who knows anything was thinking of using LK-99 for serious applications. The specs of LK-99 where just too shit. What it would have been is a start shot for understanding the effect and creating more useful materials based on the same underlying physical process.
- fluoridation 3y ago
  Thunderf00t's point, though, is that LK-99 is not novel in its material category. High temperature superconductors that are hard and brittle already existed. What would be interesting would be a malleable high temperature semiconductor, because then you can make it into cables.
  - willis936 3y ago
    There is nothing remotely close to the category of "stp superconductor". This is quite obvious when looking at a plot of critical limits of known superconductors.
  - rowanG077 3y ago
    a superconductor at 100+ degrees celsius and ambient pressures doesn't exist as of now. anything even approaching that would be earth shattering. Even if they are ceramic.
  - postalrat 3y ago
    Sounds like Thunderf00t doomed himself to be wrong no matter what happens to lk-99.
ianburrell 3y ago
Lots of superconductors aren't very good superconductors. They have a low critical magnetic field which limits the current they can carry and the magnetic field they can produce. The liquid helium cooled niobium-titanium can make strong field and is easy to produce. The RBCOs superconductors, YBCO is the main one, are liquid nitrogen cooled and make even higher magnetic fields. It sounds like it took a while to figure out how make them in bulk. YBCO superconductors are going to be revolution but will take time for the older systems to disappear. Good example is ITER, which was designed for liquid helium magnets cause nothing else was practical at the time. The SPARC tokamak from MIT uses YBCO magnets which means it can be smaller, higher field, and cheaper cooling.
penjelly 3y ago
yeah thunderfoots video really dismissed a lot of the hopes i had, and im glad for it.
scythe 3y ago
>In almost all applications of superconductors, they don't use high-temperature ones for one simple reason: Material properties. The problem is that this is not true anymore. It was true when I was in high school. Modern methods of manufacturing cuprate superconductors have been applied to the largest-scale projects: https://en.wikipedia.org/wiki/Holbrook_Superconductor_Project https://en.wikipedia.org/wiki/Holbrook_Superconductor_Projec... https://publikationen.bibliothek.kit.edu/1000075557/4402937 https://publikationen.bibliothek.kit.edu/1000075557/4402937 https://indico.cern.ch/event/775529/contributions/3309887/attachments/1828600/2993908/Minervini_HTS-for-Fusion-WAMHTS-5.pdf https://indico.cern.ch/event/775529/contributions/3309887/at...
- qayxc 3y ago
  All these use metallic (or ceramic-like with metallic properties) super conductors, though. That was the point: the material properties. If it's not metallic or exhibiting metallic-like properties (e.g. BSCCO), the practical usefulness is limited.
redox99 3y ago
Thunderfoot is more focused on being a contrarian than being accurate and unbiased. See sibling comments that explain why it being a ceramic isn't that relevant.
anabab 3y ago
Why can't regular conductors be used as such glue? i.e. you mix the ceramic superconductor powder into, say, molten copper, and make the wires out of the mix. The result would be copper wires with bits of superconductor in it. The result won't be superconducting per se, but should have less resistance than pure non-superconducting material which might be useful for certain applications.
saberdancer 3y ago
It misses the point. Ceramic "high-temp" ones are not used because they still operate at very low temperatures so you are not completely free of cooling requirements, they are just slightly lower. In that case it may make sense to use superconductor with better material properties in exchange for more cooling. A room temperature ambient pressure superconductor would remove the need for special cooling so it would be vastly better than current "high" temperature ones.

reportingsjr 3y ago

The current generation of mass manufactured high temperature superconducting tape is based on YBCO, which is a crystalline material (presumably what is meant here when saying ceramic). So the argument that superconductors need to be metallic/malleable to be useful doesn't really make a lot of sense.

kergonath 3y ago
> presumably what is meant here when saying ceramic Probably not. Being crystalline and being a ceramic are completely unrelated. Standard superconductors like niobium-tin and niobium-titanium are crystalline metals (intermetallic alloys). The vast majority of metals are crystalline, to the point that when a company tried to make a metallic glass a couple of years ago (under the name Liquid Metal), it made quite a bit of noise.
- willis936 3y ago
  That's fine but YBCO is a crystalline ceramic.
  - kergonath 3y ago
    Indeed. With a perovskite-related structure.
- jacquesm 3y ago
  > to the point that when a company tried to make a metallic glass a couple of years ago (under the name Liquid Metal), it made quite a bit of noise. https://en.wikipedia.org/wiki/Liquidmetal https://en.wikipedia.org/wiki/Liquidmetal
downWidOutaFite 3y ago
YBCO isn't really used for anything. MRI machines use metallic NbTi even though it requires liquid helium because YBCO is too brittle and can't handle large currents.

floxy 3y ago

The existing high temperature superconductors in production are also ceramics. They just deposit thin layers on another substrate and then you get flexible tapes. When you hear "second generation" HTS tapes, that is what people are referring to. AMSC and SuperPower crank it out by the mile. https://duckduckgo.com/?t=ffab&q=superconducting+tape&iax=images&ia=images https://duckduckgo.com/?t=ffab&q=superconducting+tape&iax=im...

kergonath 3y ago

> Most high-temp superconductors (including LK-99, he was assuming it was one, since he's not qualified to say one way or the other) are a ceramic. The ones that see use in the LHC, for instance, aren't. Aren’t the LHC magnets niobium-titanium? Those aren’t high temperature superconductors. Though it is indeed a metal under any definition. The rule of thumb is that high-temperature superconductors can be cooled by liquid nitrogen alone. This is not the case of the LHC magnets, which also have a liquid helium cooling loop. > They're metallic, so you can form them into the shape you need without having to manufacture it in that shape to begin with, since you'd need another superconductor to join pieces like glue, which we don't have. The term “metallic” is unhelpful because often in material science it just means an electronic conductor (a material with a non-zero density of states at the Fermi level). Under that definition, some ceramics are metallic, and the opposite of “metallic” is “insulator”, or sometimes “semi-conductor”. YBCO, which is probably the most used high-temperature superconductor, is an oxyde, so a ceramic, but still an electronic (super)conductor, so metallic. The fact that it’s an oxyde does not prevent its use, notably in spherical tokamaks. So I don’t know the person you’re referencing but their background work on the subject seems less than adequate, from what you say.

putnambr 3y ago
Did you skip over "In almost all applications of superconductors, they don't use high-temperature ones for one simple reason: Material properties." They're saying that LHC does not use a ceramic, and therefore high-temperature, superconductor; instead they use metallic (cooled) superconductors because they can be molded.
- kergonath 3y ago
  The sentence still does not make sense because the superconductors in the LHC (though, rereading it a couple of times it is somewhat ambiguous) are not high temperature by any definition. Also, again, ceramic high-temperature superconductors are metallic, or they would not be conductors. “Ceramic” and “metallic” are not mutually exclusive in material sciences. There are lots of reasons to use more classical superconductors in the LHC, just as in ITER. Some are design and engineering issues, as you mention. Another one is that the tapes we use for YBCO were not a practical thing when the LHC was designed. But now they are (though they haven’t been used in such a large scale) and you can bet that they’ll jump at any opportunity to get rid of the helium loop and take advantage of the stronger magnetic fields you can get with YBCO.

seiferteric 3y ago

I thought it was a poor point. The paper proposed a new mechanism for the superconductivity, which would have been a bigger deal than this specific formulation (lk-99). If it were true, it would be a new class of superconductors which I would think this would lead to development of new formulations that perhaps had better properties. Plus as others have said, superconductor material can and is deposited on tapes (see ReBCO) to make it usable.

EvgeniyZh 3y ago
They didn't propose new class of superconductors. They conjectured that LK99 follows some 25-year-old theory from a paper written in Korean. Leaving alone the fact that the theory doesn't make much sense to me (at least the parts I managed to understand), there was no evidence in the LK-99 paper that this mechanism is indeed what makes LK99 superconductive (or more precisely that it is present in LK99).

rowanG077 3y ago

The problem, which is often the case with Thunderf00t, is that he is missing the forest for the trees. No one who knows anything was thinking of using LK-99 for serious applications. The specs of LK-99 where just too shit. What it would have been is a start shot for understanding the effect and creating more useful materials based on the same underlying physical process.

fluoridation 3y ago
Thunderf00t's point, though, is that LK-99 is not novel in its material category. High temperature superconductors that are hard and brittle already existed. What would be interesting would be a malleable high temperature semiconductor, because then you can make it into cables.
- willis936 3y ago
  There is nothing remotely close to the category of "stp superconductor". This is quite obvious when looking at a plot of critical limits of known superconductors.
- rowanG077 3y ago
  a superconductor at 100+ degrees celsius and ambient pressures doesn't exist as of now. anything even approaching that would be earth shattering. Even if they are ceramic.
- postalrat 3y ago
  Sounds like Thunderf00t doomed himself to be wrong no matter what happens to lk-99.

ianburrell 3y ago

Lots of superconductors aren't very good superconductors. They have a low critical magnetic field which limits the current they can carry and the magnetic field they can produce. The liquid helium cooled niobium-titanium can make strong field and is easy to produce. The RBCOs superconductors, YBCO is the main one, are liquid nitrogen cooled and make even higher magnetic fields. It sounds like it took a while to figure out how make them in bulk. YBCO superconductors are going to be revolution but will take time for the older systems to disappear. Good example is ITER, which was designed for liquid helium magnets cause nothing else was practical at the time. The SPARC tokamak from MIT uses YBCO magnets which means it can be smaller, higher field, and cheaper cooling.

penjelly 3y ago

yeah thunderfoots video really dismissed a lot of the hopes i had, and im glad for it.

scythe 3y ago

>In almost all applications of superconductors, they don't use high-temperature ones for one simple reason: Material properties. The problem is that this is not true anymore. It was true when I was in high school. Modern methods of manufacturing cuprate superconductors have been applied to the largest-scale projects: https://en.wikipedia.org/wiki/Holbrook_Superconductor_Project https://en.wikipedia.org/wiki/Holbrook_Superconductor_Projec... https://publikationen.bibliothek.kit.edu/1000075557/4402937 https://publikationen.bibliothek.kit.edu/1000075557/4402937 https://indico.cern.ch/event/775529/contributions/3309887/attachments/1828600/2993908/Minervini_HTS-for-Fusion-WAMHTS-5.pdf https://indico.cern.ch/event/775529/contributions/3309887/at...

qayxc 3y ago
All these use metallic (or ceramic-like with metallic properties) super conductors, though. That was the point: the material properties. If it's not metallic or exhibiting metallic-like properties (e.g. BSCCO), the practical usefulness is limited.

redox99 3y ago

Thunderfoot is more focused on being a contrarian than being accurate and unbiased. See sibling comments that explain why it being a ceramic isn't that relevant.

anabab 3y ago

Why can't regular conductors be used as such glue? i.e. you mix the ceramic superconductor powder into, say, molten copper, and make the wires out of the mix. The result would be copper wires with bits of superconductor in it. The result won't be superconducting per se, but should have less resistance than pure non-superconducting material which might be useful for certain applications.

saberdancer 3y ago

It misses the point. Ceramic "high-temp" ones are not used because they still operate at very low temperatures so you are not completely free of cooling requirements, they are just slightly lower. In that case it may make sense to use superconductor with better material properties in exchange for more cooling. A room temperature ambient pressure superconductor would remove the need for special cooling so it would be vastly better than current "high" temperature ones.