There was great euphoria when about two weeks ago a potential new superconductor caused a stir in the media. The disillusionment is now also great: So far, the material LK-99 could not live up to the hype.
What has happened so far? A group around the physicist Karsten Held from the Technical University of Vienna is cautious. Their results are partially compatible with a new superconductor – but there is no definitive confirmation, as Der Standard writes. The results of Chinese researchers have also shown that the behavior of LK-99 can also be explained without superconductivity, reports Golem.
According to the current state of knowledge, a superconductor that functions at normal pressure and normal room temperature remains science fiction. For now – or forever? We stay tuned for you.
Scientists around the world are currently trying to repeat the supposed research results around LK-99.
For example, the physicist Sinéad Griffin from the Lawrence Berkeley National Laboratory tweeted: »In my work, the superconductivity of lead apatite was not verified or proven.«
Many well-known research institutions are still experimenting.
The US superconductor researcher David Larbalestier writes: »Within a week or two we will have 20, 30, 40, 50 or 100 laboratories that have carried out different syntheses. So it will be clear pretty quickly [ob LK-99 wirklich ein Supraleiter ist].«, as quoted on The Verge.
So is LK-99 really a superconductor? We’ll know soon. We keep a healthy dose of skepticism – but also hope.
Until now, researchers could only dream of such a breakthrough – and now they want to have discovered it.
A superconductor that also works at normal pressure and below room temperature would be groundbreaking. If such a superconductor was actually discovered, it would have far-reaching consequences for computers and electric motors – or simply for the mobile phone in your pocket.
Imagine extremely powerful computers that produce no heat. Or think of power plants or power grids with 100 percent efficiency. Not to mention the application for high-speed trains.
Researchers at the Quantum Energy Research Center in Seoul and the College of William & Mary in Virginia now want to have discovered just such a superconductor.
But what is really behind it?
What are superconductors – simply explained?
Superconductors are certain materials that conduct electronic currents at very low temperatures – without any electrical resistance. We remember the physics lessons from school: electrical resistance describes how well or badly a material allows the flow of electric current.
Here is an example from everyday life: If current flows through a wire, an electrical resistance can always be observed. This resistance leads to energy loss. You can observe the same loss from the heat emanating from the wire.
What did the researchers discover?
July 22, 2023: The researchers from Korea and the USA published their study results on this date.
Lead apatite is the mineral, which is supposed to serve as a new superconductor. In order to elicit its superconducting abilities from lead apatite, the researchers proceeded as follows:
🧪 lead atoms by copper substitute. In other words, lead apatite is, so to speak, contaminated with copper atoms. In technical jargon, the term “contaminate” is not used, but rather “dope”.
🧪 Craft Alloy: The team mixed different powders made from chemical compounds of lead, oxygen, sulfur and phosphorus. This mixture was baked for several hours, as Der Standard writes. The result is an alloy of said compound.
👩🔬 Result of this test arrangement: A thin gray plate. The supposed miracle material was baptized with the name LK-99.
What properties have been observed in LK-99?
In order to find out the suitability of the gray platelet as a superconductor, it was subjected to a number of tests to answer important questions.
❓ How high or low is the critical temperature below which superconducting property becomes observable? When the researchers cooled the plate from 105 degrees Celsius to 30 degrees, the electrical resistance is said to have dropped to zero. For comparison: Superconductors normally need a temperature of minus 140 degrees to function, as n-tv and Süddeutsche write.
❓ Can we observe the Meissner-Ochsenfeld effect? This effect allows superconductors to levitate above magnetic fields. Like that? The Meißner-Ochsenfeld effect describes the behavior of superconducting materials in relation to an external magnetic field. In practical terms: previously known superconductors have to be cooled down considerably in order for them to become superconducting. Once this particularly low temperature has been reached, two properties can be observed in the material:
- Total magnetic field exclusion: Simply put, the magnetic field no longer penetrates into it interior of the material a. Instead, the magnetic field is repelled by the surface of the material.
- Perfect diamagnetism: That means that too external magnetic field is resisted. This causes the material to levitate as soon as it is above a magnet.
But see for yourself how a test piece levitates above a magnet. The scientists responsible have published a video about it.
But the video from above is also subject to criticism. Because the effect can also be observed with non-superconducting graphite.
What would such a superconductor mean for us?
Today, superconductors are mainly used in medicine and research. For example in MRI machines or particle accelerators. Magnetic resonance imaging equipment is used to create images of the inside of your body. Superconductors are also used in the particle accelerator at the CERN nuclear research center.
But why are superconductors rarely found in other areas? The answer: superconductors as we know them today have to be constantly cooled with liquid helium. This continuous cooling is expensive and complex.
That is why the discovery of a superconductor that works below room temperature would be so groundbreaking.
Because of this – and because of the numerous possible applications. »CPUs do not develop heat« or »more efficient electric motors« are promised by Der Standard.
By the way: If you want to learn more about superconductors and how they work in a technically competent and easily digestible way, we recommend the following video by the German physicist Sabine Hossenfelder.
Link to YouTube content
How credible is the study?
The research work of the Koreans is currently still speculative in nature. Only when the work from the Far East has gone through the so-called peer review process can the results of the researchers be considered reliable.
Criticism from the scientific community: However, other steps are also recommended if they would be beneficial to scientific quality assurance, as experts believe. The following points are important to note.
✅ Lack of reproducibility: In Der Standard the physicist Wolfgang Lang is quoted with critical words. Although Lang finds the research results promising, he is also suspicious, because he says: “I see no evidence of the reproducibility of the measurements on several samples.” The physicist also considers the small amount of sample material to be strange.
✅ Confirmation or challenge of research results: “Is it really a superconductor?” In order to answer this question, the involvement of independent laboratories would be helpful. In other words: Can other scientists at other research institutions repeat the test?
What’s next for the superconductor LK-99?
There is also competition in the scientific community. In the past, this, or research results that were easy to correct, repeatedly led to reports of new superconductors – which had to be put into perspective afterwards.
Examples include a study by the University of Rochester. Here, too, a superconductor was discovered that should function at room temperature. However, this still requires a very high pressure, as in the deep sea.
What happens to LK-99 now? According to the popular journal Science, it only takes a few weeks to review the research from Korea. Hyun-Tak Kim and team want to support any researchers who want to repeat the experiment.
Is this discovery from Korea comparable to the transistor – or will the researchers soon have to backtrack? Are you as critical as your colleagues? Write us your opinion in the comments.