The suspicion of room-temperature superconductivity that has caused a sensation in the global scientific community may be another "wolf is coming" story.
After many research institutions around the world failed to reproduce the so-called room-temperature superconductor LK-99 conducted by Korean researchers, South Korea's local superconducting research institutions reviewed the project and finally concluded that, based on the existing evidence, it is impossible to Prove that LK-99 is a room temperature superconductor.
According to Yonhap News Agency, the "LK-99 Verification Committee" setup by the Korean Superconducting Society stated that no "Meissner effect" was observed in the videos and papers related to LK-99.
The cái gọi là Meissner effect, that is, the unique "complete diamagnetism" of superconductors. Ordinary materials are in a magnetic field, and the magnetic force lines usually pass through them, but the magnetic field inside the superconductor is always equal to 0, which can bounce the magnetic force lines away and suspend them in the air.
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(Nếu bạn don't hiểu the Meissner effect, you can also watch the Meissner effect experiment demonstrated by Mr. Gu Chen, Department of Physics, Tsinghua University today, which is very intuitive)
The verification committee told Yonhap News Agency that in addition to the Meissner effect, superconductors will also exhibit a "flux pinning" effect when reacting with a magnet, that is, the superconductor will be fixed at a specific position above the the magnet.
The levitation video of LK-99 is far from the magnetic flux pinning effect. The video shows that the LK-99 is not stable when levitating and will keep shakeking in the air. In addition, the LK-99 research team also admitted in a paper uploaded to arXiv that when reacting with a magnet, only a part of the sample can be suspended in the air, not the complete sample. The verification committee believed that the sample might simply be moving away from the magnet due to diamagnetism, rather than exhibiting the Meissner effect.
In addition, the verification committee noted that the data in the paper also differ from typical superconductor diagrams. For superconductors, the magnetic susceptibility returns to zero at the critical temperature, but LK-99 shows a negative value.
The verification committee believes that the magnetic supibility change diagram of LK-99 also only shows diamagnetism, and many materials that are not superconductors also have diamagnetism.
Phỏng vấn xác minh ủy ban thành viên nói Yonhap Tin tức Cơ quan:
"Our position has not changed and the current data are inenough to prove that LK-99 is a room temperature superconductor."
It is worth pointing out that the above verification was carried out without contact with LK-99 samples.
The Verification Committee has requested the team of the Korea Institute of Quantum Energy Research to provide LK-99 samples, but the team said that because the submitted papers are under review, the samples cannot be for the time being, and they need to wait until the review is complete, which may take 2-4 week.
The members of the verification committee interviewed said that once they can touch the sample, they only need to measure its magnetic supibility and resistance to see if LK-99 has the complete diamagnetism and zero resistance of a superconductor, and the truth will soon be revealed.
