The few videos of lk99 show it reacting to a singular magnet. A property of superconductors that apparently diamagnetic materials don't have.
It'll react fine to a singular magnet, it just won't be stable enough to levitate - that's why the videos show casing replication of diamagnetism show it standing on end.
The diamagnetism, importantly this means repulsion of both poles simultaneously and equally (this is how you can have these magnets spin, a regular magnet repels same poles and attracts opposites, diamagnets repel both poles), is simply a characteristic of the superconductor, but it alone would just repel the object off.
Here is a timestamped link to NileRed’s YBCO video that visually describes the flux pinning:
https://m.youtube.com/watch?v=RS7gyZJg5nc&t=1887
And here’s a timestamped link to Ben Krasnow’s Applied Science YBCO video where he shows a close up of the crystal’s cross section that shows the imperfections that allow the magnetic field through for the pinning effect:
Timestamp: https://youtu.be/RS7gyZJg5nc?t=2496
It goes to show how difficult manufacture, or in the case of the LK-99 news cycle “reproduction”, of these materials really is, and YBCO was a well documented area of superconductor manufacture.
There is a video from the Korean team showing LK99 moving when both poles of a large magnet is swung nearby, however the effect was a bit weak to conclusive.
https://m.youtube.com/watch?v=Ws6AAhTw7RA&t=90
If we develop methods of creating these superconductors with perfect crystal composition then there will only be the repulsion, allowing for levitation in a bowl shaped superconductor, but this “hanging levitation” would be impossible.
Perhaps we will develop manufacturing techniques to induce specific imperfections into the material to ensure predictable flux pinning.
What's strange is that drop at higher temps, that's either a measurement anomaly or something really odd.
Do you think it will be "purity" or understanding material variance/specific impurity?
It reminds me of Fogbank, the nuke material claimed to be "so secret they forgot how to make it." Part of the story of manufacturing difficulty was due to increased purity of modern materials/processes.
In a bizarre twist, the new production facility and reverse-engineered production process yielded a version of Fogbank that was of a higher purity than it had been in the past, according to the article. The problem, however, was that for Fogbank to work as intended in existing warhead designs, that previous level of impurity was actually essential. NNSA had to revise the process to ensure the final product was just as impure.
https://www.thedrive.com/the-war-zone/32867/fogbank-is-myste...
It could be either.
As I pointed out in other comments, that's how radioactivity was discovered and it is very well possible that they blundered into something exceptional by accident, it is also possible that both parties got it wrong and there are yet other effects at play (see the big gap in the t/R curve, that really needs explaining).
When Hildebrand ran the baths the silver came out bright, and stuck to the objects; the minute he left troubles started. No one knew why. Shortly before he left to go into the antique business in Charleston he showed me the secret. It was his chewing tobacco, spat into the bath from time to time. From then on, one man in each shift chewed, and the problem was solved
Any other recommendations on books about the history of MatSE/Chemistry?
Oops... I can see where that is headed.
Ignition! By John D. Clark
https://www.amazon.com/Ignition-audiobook/dp/B07CTW1M9D/ref=...
Or, maybe you’ve already read it, in which case: great job. Maybe someone else will see this comment and enjoy it.
I don’t want to spoil if for you, but I loved the last paragraph. I believe a new heroic age for the field is dawning.
This book is probably helping me cope with the extreme confusion of all the various LK-99 attempts. Like, it's going to be a hugely messy confusion and slog with lots of results that are "blend-A can meet 5 of the 7 requirements, but not the important ones. blend-B can meet 3 of the 7, but one of the important ones. blend-C looks very promising but doesn't quite meet any of the requirements." for... years.
https://en.wikipedia.org/wiki/LK-99#Replication_attempts
> Claimed to have synthesized LK-99 and to have measured superconductivity up to a temperature of 110 kelvin. Claimed to have observed an abrupt drop in resistance between ~300K and 220K, aligning with the Korean LKK team's results. Claimed to have confirmed structural consistency with x-ray diffraction.
Replication is difficult, and particularly difficult for novel processes where the important variables are not well understood. It could be that the methods were reported as accurately as possible but still leave out critical detail(s).