Been following this very closely. Seems like the one takeaway is that whatever material this is, it's interesting. It's also difficult to synthesize in bulk, which is a shame because superconductivity is not easy to observe in non-bulk materials (think: powder).
Note: I have a physics degree and a little bit of condensed matter experience, but nothing like anyone actually working in the field. Just some graduate courses and a bit of lab work experience.
Assuming LK99 is legitimate, my hope is that the principles that make it work are more broadly applicable - and with that, refined production processes or newer alloys can be found. Simply knowing that it's possible would lead to a huge amount of research immediately focusing on this kind of thing.
There's nothing more revolutionary than a discovery of a new class of materials. After all, we often name eras throughout our history after them :) (Stone age, etc)
> There's nothing more revolutionary than a discovery of a new class of materials. After all, we often name eras throughout our history after them :) (Stone age, etc)
I wonder what was involved in the discovery of stone.
Abstract: Our rigorous dialectic treatment shows that stone, while well suited for the smashing open of certain types of nut, is not well suited for any other purpose. Advocates from the more radical fringes of the tribe who suggest stone may be employed in varied areas such as warfare or even homebuilding(?!), are herein put in their proper place.
There are many different types of stones, and techniques for shaping them became progressively more sophisticated over time.
With instruction, it would probably take you less than an hour to learn how to make the types of simple chopping stones that human ancestors used 1 million years ago. However, it takes much more considerable time and skill to learn how to make the types of stone tools humans were using 100k years ago. You get the sense that each group of ancient humans probably had an old expert toolmaker who passed on the trade to the next generation.
It just occurred to me that this might relate to why people get near sighted with age. An old tool maker may no longer be as productive in hunting and gathering but instead masters his or her craft thus aiding the tribe.
The variables that lead to its formation are not all accounted for yet. The process is understood, but it doesn’t always work. So there must be something missing every now and then.
Wild guess is that the dopant that creates wells doesn't always end up where it should. The paper that claimed superconductivity in layers of graphene at very particular angles also seems to be very sensitive. A similar one claimed graphene with alkanes was observed to superconduct. Perhapes whatever impure hydrocarbon they were using held the sheets at the perfect angle. All the quantum wells these things are claiming to rely on seem terribly difficult to arrange perfectly enough to work consistently. Assuming any of them ever did.
No indeed. Lots of this in our history. You can't do most of electronics without semiconductors. But, if you have no idea what's going on you can make some rudimentary electronics experiments work - unreliably - without knowing that - e.g. the "Cat's whisker" crystal radio technology. The reason this actually works is because it's a semiconductor, but since you don't know what those are yet, you just know if you fiddle about with a fine wire and certain types of crystal, sometimes it does what you wanted, and if it doesn't keep fiddling with it until it does.
I'd imagine early history of sugar products is the same. Today you can precisely control the temperatures and so you can engineer getting exactly the desired products from sugar, but if you're not so good at either measuring or keeping careful control of temperature, you get... something. It's sugar so in most cases it's delicious anyway, but if you wanted fudge but you've made toffee you may be disappointed. With practice you can "eyeball" it without better equipment, like the cat's whisker, but with better equipment an idiot with no experience can make it do what they wanted because the numbers were correct.
Samurai sword making took what, a thousand years of trial and error? The forgers had no idea how making steel worked, they just found a way to make it work.
I have repeatedly read that Japan has poor quality iron, but what exactly does that mean? Iron is an element, so all of the reserves were in an unfortunate oxide requiring sophisticated refining? Just low total abundance?
Notably phosphorus is very hard to get rid of when it's in your metal. Before better metallurgy, the best steel worldwide was made out of low-phosphorus ores.
Getting a pure ingot of iron is no simple task if you don't have access to a good furnace. So you'll end up with 'bad' (impure) iron if it doesn't come out of the ground in reasonably pure chunks.
Or bread… have you ever thought what must’ve gone through somebody’s head to think of grinding all those cereals, adding random stuff, and baking it? How the heck did anybody come up with that??
Yes, based on the materials and type of process, it seems like the default assumption should be, if it's real at all, it's going to be a tweaky, unreliable process at first. A more surprising result would be if the published process reliably works 100% of the time.
The theory is the crystal structure induced by oxidation and vibration is responsible for the superconducting effect. They literally dropped and cracked the quartz ampoule by accident and produced the sample.
Its not enough to produce the material itself, it seems it is an emergent property of the structure and formation of the material similar to piezoelectric effect?
>So they have a batch of the material as proof, but no idea how to exactly reproduce it?
No, we don't know how to reproduce it, with "we" being everyone not on the South Korean team.
The papers everyone is trying to work from to replicate this are the "leaked" arXiv papers. That actual peer reviewed paper is still in process, and presumably that one includes more information on how to replicate the material.
Given the sheer amount of samples material scientists may produce I imagine accidentally hitting your target characteristic through impurities rather than direct formula may happen more often then they care to admit. That being said even if they haven't actually narrowed down on the exact formula knowing it can even happen in the first place is a major discovery
The first time it demonstrated superconductivity they dropped the quartz tube it was in, cracking and accidentally oxidizing it at a specific point in the heating process and providing vibration that caused the formation of a crystal structure in the material.
That would be better than the physics equivalent of cold fusion (which seemed promising at first, but turns out to not exist - at least so far). Only time will tell, though if it really is, but so difficult to replicate that we need a few hundred years it may as well never exist for purposes of our lifetime.
I don’t have really any expertise here but it looks like it bakes into a powder pretty much every time. Sure you get LK-99, but you can’t measure superconductivity in a powder since it’s a bulk property.
It's not clear exactly what compound constitutes "LK-99" because the equations in the papers are unbalanced and the synthesis is ill defined. What they say they got doesn't make sense for how they say they got it. Most likely it's a mixture of compounds, any of which could be producing the alleged superconducting phenomena.
Yup, and the "preprint" (which doesn't have a number of controls in the process) leaves a lot to be desired, so the "real" paper will presumably have some of this worked out.
I expect things like the cooling rate (which affects crystal growth) and oxidation will both have variability in them.
Paper mentions amorphous state plus an annealing step. Should be glass like at the end. If so, heat rates (up and down) of the last step are important and hardly mentioned.
Is there any hard limitation that prevents synthesizing in bulk? If not, I would not worry about this at the moment and if it proves to be a material with desirable properties just leave it up to the engineers who will hopefully find a suitable production process.
There’s not really such a thing as superconductivity for a fine powder, so people are having trouble determining if this material even superconducts.
edit to clarify: Bulk here refers to having a single chunk of the material, and does not refer to the total quantity. Some physical properties only exist or only surface in chunks of material, not in the powder form.
Conversely, the tape-type high temperature superconductors are generally made with a colloidal deposition process - which is based on a powder as a starter material.
Assuming this is real, that would be the obvious process by which to try and build useful conductors and magnets - it also suggests a refinement process (passing it over a magnet would quantum lock superconducting grains and let the rest slide off).
Note: I have a physics degree and a little bit of condensed matter experience, but nothing like anyone actually working in the field. Just some graduate courses and a bit of lab work experience.