5 ms·

So a completely different compound in a completely different shape.

depereo 3y ago
Still helpful. Now people know this synthesis process and result doesn't have this desired property and the 900 other groups working on this don't need to repeat it.
xqcgrek2 3y ago
The XRDs are nearly identical. It's a dead horse.
- ycui1986 3y ago
  XRD used here only shows crystal lattice information for random orientated polycrystalline. It does not mean the two samples are identical. It does not prove whether they had single crystal or polycrystal. You will need a four-circle diffractometer to prove two samples are identical, that also only work on single crystal if anyone can make it.
- carabiner 3y ago
  XRD comparison isn't from eyeballing. The fact is, the original papers do not coherently specify "LK-99" because their equations, synth procedure, and subsequent analysis are all incomplete or contradictory. It's like they gave everyone 2 + 2 = 5 and so everyone's been trying to figure out how to get to 5, while also questioning 2 and 5 because the quality of the papers is so poor. "We do not know the composition or structure of #LK99 with any confidence." https://twitter.com/Robert_Palgrave/status/1687235756702752768 https://twitter.com/Robert_Palgrave/status/16872357567027527...
XorNot 3y ago
Different but reproducing the only real current "signature" LK99 behavior anyone's been able to show. That a definitely non-superconducting material can do something similar is bad news for LK99.
GuB-42 3y ago
Yes, but I take it like a rebuttal. They got the same effect that got everyone excited (half levitation) with a similar material that is ferromagnetic. Considering that there is a lot of unknowns and randomness regarding the synthesis of LK-99, and that the half levitation effect can be explained by ferromagnetism, to me, it sounds much more likely that the original LK-99 is a ferromagnet rather than a superconductor. Simply because ferromagnets are common, and a room temperature superconductor is an extraordinary claim. I'd like to be wrong, but for now, it doesn't look good for superconductivity.
- throwawaymaths 3y ago
  This is bad logic. Ferromagnetic explains half levitation but it doesn't explain full levitation. Superconductivity is sufficient to explain full levitation and half levitation. > Simply because ferromagnets are common Sure, metal ones are, but Are ceramic ferromagnets (without iron) common? That lone electron in an orbital is pretty important.
  - Jweb_Guru 3y ago
    > Ferromagnetic explains half levitation but it doesn't explain full levitation No one reputable has actually demonstrated full levitation, including the original team. > Sure, metal ones are, but Are ceramic ferromagnets (without iron) common? That lone electron in an orbital is pretty important. They literally reproduced this behavior with a substance that looks identical to the original LK-99, so while it would be quite unusual, it is clearly possible. Apparently ferromagnetism without any ferromagnetic compounds has been witnessed before, e.g. in ZnO.
    - throwawaymaths 3y ago
      Never claimed it was impossible, just that it's rare. > No one reputable I don't care about reputability of anyone unless they have a known past of fraud. Gatekeeping in science is lame unless someone makes a claim to break well understood theory or claims to do something technically difficult. RTSC is neither. Do you think this video is faked?: https://twitter.com/Andercot/status/1687740396691185664?s=20 https://twitter.com/Andercot/status/1687740396691185664?s=20
hliyan 3y ago
Yes, but it allows for an Occam's Razor explanation of the observations so far.

Still helpful. Now people know this synthesis process and result doesn't have this desired property and the 900 other groups working on this don't need to repeat it.

xqcgrek2 3y ago

The XRDs are nearly identical. It's a dead horse.

ycui1986 3y ago
XRD used here only shows crystal lattice information for random orientated polycrystalline. It does not mean the two samples are identical. It does not prove whether they had single crystal or polycrystal. You will need a four-circle diffractometer to prove two samples are identical, that also only work on single crystal if anyone can make it.
carabiner 3y ago
XRD comparison isn't from eyeballing. The fact is, the original papers do not coherently specify "LK-99" because their equations, synth procedure, and subsequent analysis are all incomplete or contradictory. It's like they gave everyone 2 + 2 = 5 and so everyone's been trying to figure out how to get to 5, while also questioning 2 and 5 because the quality of the papers is so poor. "We do not know the composition or structure of #LK99 with any confidence." https://twitter.com/Robert_Palgrave/status/1687235756702752768 https://twitter.com/Robert_Palgrave/status/16872357567027527...

XorNot 3y ago

Different but reproducing the only real current "signature" LK99 behavior anyone's been able to show. That a definitely non-superconducting material can do something similar is bad news for LK99.

GuB-42 3y ago

Yes, but I take it like a rebuttal. They got the same effect that got everyone excited (half levitation) with a similar material that is ferromagnetic. Considering that there is a lot of unknowns and randomness regarding the synthesis of LK-99, and that the half levitation effect can be explained by ferromagnetism, to me, it sounds much more likely that the original LK-99 is a ferromagnet rather than a superconductor. Simply because ferromagnets are common, and a room temperature superconductor is an extraordinary claim. I'd like to be wrong, but for now, it doesn't look good for superconductivity.

throwawaymaths 3y ago
This is bad logic. Ferromagnetic explains half levitation but it doesn't explain full levitation. Superconductivity is sufficient to explain full levitation and half levitation. > Simply because ferromagnets are common Sure, metal ones are, but Are ceramic ferromagnets (without iron) common? That lone electron in an orbital is pretty important.
- Jweb_Guru 3y ago
  > Ferromagnetic explains half levitation but it doesn't explain full levitation No one reputable has actually demonstrated full levitation, including the original team. > Sure, metal ones are, but Are ceramic ferromagnets (without iron) common? That lone electron in an orbital is pretty important. They literally reproduced this behavior with a substance that looks identical to the original LK-99, so while it would be quite unusual, it is clearly possible. Apparently ferromagnetism without any ferromagnetic compounds has been witnessed before, e.g. in ZnO.
  - throwawaymaths 3y ago
    Never claimed it was impossible, just that it's rare. > No one reputable I don't care about reputability of anyone unless they have a known past of fraud. Gatekeeping in science is lame unless someone makes a claim to break well understood theory or claims to do something technically difficult. RTSC is neither. Do you think this video is faked?: https://twitter.com/Andercot/status/1687740396691185664?s=20 https://twitter.com/Andercot/status/1687740396691185664?s=20

hliyan 3y ago

Yes, but it allows for an Occam's Razor explanation of the observations so far.