Superconductor Levitates At Room Temperature, But Questions Remain

It may be just another day for you and me, but the worldwide scientific community is still working around the clock to verify claims of a new superconductor that might yet revolutionize human civilization. Now, scientists with the Huazhong University of Science and Technology claim to have replicated LK-99’s levitation abilities at room temperature, which they showcased in a video uploaded to Bilibili.

This is an encouraging sign: one of superconductivity’s hallmarks, magnetism due to the Meissner effect, seems to be a replicable feature of the copper-lead-apatite compound. If only it were “that easy” to confirm (and understand) the material’s zero electric resistance capability and how it manifests.

Related Articles

The clear-cut update is this: despite the fact the researchers could replicate LK-99’s levitation at room temperature, there’s still no successful replication of the announced room-temperature LK-99 superconductivity. For that to happen, both the Meissner-effect magnetic field and zero electric resistance are required from the same sample. And while scientists have previously shown that LK-99 does have zero resistivity at -163C, they haven’t yet proven it has those properties at room temperature.

So what we’re left with (still) is several failed or partially failed replications – and a whole world of additional knowledge on LK-99. The Wikipedia live tracker is one of the best places for anyone looking for up-to-date information on the (public) replication processes currently underway.

The replication difficulties and the nebulous history around superconductors (which have seen several similar room-temperature superconductor claims announced, published, and retracted) combine into a visible, waving, giant red flag. So remember to remove your rose-colored glasses. LK-99 is a fickle thing, and the ground it’s standing on is filled with question-shaped potholes.

As our understanding of LK-99 improves, the fuzzy road ahead become slightly clearer. Unfortunately, it seems that the material’s characteristics themselves may both be its boon and its blight. That’s not to mention the fact that the original scientists did a shoddy job of documenting how they created the material, leaving scientists to patch together samples with a somewhat incomplete cookbook.

As we’ve explored before, LK-99 is a compound made from reacting lead sulfate with a copper-phosphorous compound. The process through which this compound becomes LK-99 requires that the materials be baked at high temperatures for more than 24 hours in a vacuum. This is slightly easier to achieve than it sounds, as several Twitter/X posts and videos of people “owning their own LK-99” will show you (there’s also the eternal memory of a Russian soil scientist and her kitchen counter as the first claimed independent synthetization of LK-99). 

And adding great to good, the materials aren’t even expensive to procure — the materials are all relatively cheap and abundant. But the biggest problem with LK-99 doesn’t seem to involve its synthetization; the problem is the lack of control over the chemistry and quantum processes that occur during the fabrication process itself.

Crystals, it turns out, are fickle things. And the way LK-99 seemingly becomes a superconductor has to do with how many lead particles are replaced by copper. As it stands, it seems that the more copper that replaces lead in the final mixture, the purer the resulting compound is (which translates into it showcasing both the emergent levitation courtesy of the Meissner and zero resistance to electrical conductivity). 

But that is both the solution and the problem; for now, there’s no way for researchers to know what the synthetization process will actually do at an atomic level. So the scenario we’re arriving at is that sometimes, there may simply not be enough superconducting elements in a given LK-99 batch for it to showcase any of the superconductive properties we’re all hoping it does. It’s actually in the formula: the “x” values in Pb10-xCux(PO4)6O, as it’s represented in chemistry parlance, mean that it’s uncertain just how many of the 10 base lead atoms are replaced with copper atoms. But it seems that the higher the number, the better.

To complicate things even further, however, it’s not just a case of having as many copper atoms replace lead as possible; the places where these substitutions occur in the crystal also matter. It seems that some locations are better for unlocking LK-99’s superconducting capabilities than others, and for now, once again, we have no way to “pick and choose” what happens during the synthetization process.

Adding insult to injury, the same LK-99 batch can have different ratios of copper atoms replacing lead across its volume. Some will be high, which is good for levitation and bringing a twinkle of excitement to our eyes; some will be low, resulting in a mostly inert compound that would be better used as a doorstop.

And that’s saying nothing about how even the most random and seemingly insignificant variances in any of the synthetization steps can introduce unknown variables into replication attempts themselves — especially when researchers are following already badly-documented processes.

Cue the number of failed replication attempts, which, if all this pans out, is likely to keep increasing until it comes to a point where we can design a new synthetization process that improves yield. With all these moving parts, however, it’s no wonder we’re still walking across a dark room.

None of these difficulties are a definite chink in LK-99’s aspirations. But the cards have been mostly dealt. It remains to be seen who (if anyone) grabs the winning hand. Nobel prizes have been handed out for less, after all.