Shulou(Shulou.com)11/24 Report--

The preliminary results of the normal temperature and normal pressure superconductivity experiment, which has attracted much attention from the global physics community, are newly released!

Professor Sun Yue of Southeast University (B Station Up Master "Science Investigation Bureau") announced the whole process:

Without saying much, he directly reported the results:

I didn't see any signals that might be superconducting.

By the time of publication, the video had more than 1 million views, which really attracted a lot of attention.

Professor Sun, who has more than a decade of research experience in the field of superconductivity, has previously expressed "skepticism" about the new research by the South Korean team. So how exactly did this replication experiment work? Let's move on.

(Note: This article has been authorized by Professor Sun.)

Professor Sun Yue and Professor Shi Zhixiang paid attention to the new study on July 25 and decided to purchase raw materials on the same day. On the second day, the raw materials arrived, and the team decided on the experimental protocol.

The first step of the experiment is to synthesize precursors, Lanarkite and Cu3P respectively.

In this step, the team placed the materials in an argon protected glove box to prevent oxidation, and then weighed and balanced the raw materials.

After balancing, the team still grinds the raw materials in the glove box to mix them thoroughly.

The second step of the experiment is to put the raw materials into the quartz tube and evacuate according to the paper.

However, Professor Sun and Professor Shi said that there were contradictions in the previous papers, that is, the text part said "there is air," but in the chart it is "high vacuum."

So, in this step, the team placed one part of the raw material in a vacuum-tight state and the other part in air.

Next, it came to the "alchemy" link. The team put both raw materials into a high-temperature furnace in the laboratory for sintering.

Professor Sun and Professor Shi said that this step alone consumed two days of their time:

Because according to the paper, it takes 48 hours to sinter.

Finally, on July 29, the team obtained the sintered precursor.

It is worth noting that in order to prevent the raw materials from being oxidized or wetted in the air, the team opened the raw materials in the glove box, ground them, and X-ray diffraction (XRD) analysis.

It is worth noting that the XRD data of Professor Sun and Professor Shi's team are consistent with those in the paper.

The next step was to continue synthesizing the target material.

However, at this time, Professor Sun and Professor Shi's team found another problem in the thesis.

In Korean research, the ratio of copper and phosphorus in the final product produced by the reaction of two raw materials is 1:6, but the precursor is Cu3P after all, so it is difficult to balance the equation.

Therefore, Professors Sun and Shi tried two different combinations.

In addition, the sintering of precursors is also in vacuum and oxygen environment, and the synthesis conditions in the paper are 925℃, 5~20 hours. The team decided to take two different conditions, 10 hours and 20 hours.

Adding all these variables together, the team ran eight experiments. Finally, it came to the experimental demonstration.

In the superconducting magnetic levitation experiment, as mentioned above, the sample lies firmly on the magnet, and the ideal result does not appear.

Later, the team conducted magnetization measurements on the sample, and the results showed that there was still no sign of superconductivity.

However, this result does reflect some negative magnetization signals, indicating that the sample has very weak diamagnetism. It is also because the signal is very weak that it cannot be completely ruled out as a result of impurities.

Later, Professor Sun and Professor Shi's team measured the hysteresis curve (M-H Loop) of the sample at 200K. From the results, the sample exhibits weak ferromagnetism (possibly due to impurities).

As far as the results published so far are concerned, no evidence of superconductivity has been seen in Professors Sun and Shi's replication experiments.

But the team still has seven different samples, and they will measure them in turn according to the steps described above.

Still to be verified For this result, Professor Sun said in the video that it was only "preliminary":

The possibility of superconductivity of this material cannot be ruled out, and further purification and various measurements are needed.

Including copper content, there is still a lot of room for regulation.

Just yesterday, the Korean team's research was exposed to an unexpected discovery, that is, the quartz tube was prepared after cracking.

In response, we contacted Professor Sun:

This is something our team hasn't tried yet.

Quartz tube ruptures can occur in two ways for us. The first is to adjust the process, that is, to add some oxygen; the second is to take the sample out at high temperature and quench it to obtain a more stable phase.

But I don't think these are the core problems, because the results of our sample structure analysis are exactly the same as theirs.

It is possible that their operation caused some small structural distortion in the sample.

One More Thing As the popularity of the experiment rose, some netizens compiled a global "competition list." Interested friends can pay attention:

In addition, Professor Hyun-Tak Kim, one of the authors of the paper, said the revised paper was republished on arXiv today, according to the Daily Economic News.

As for where the end result will be, let the bullets fly a little longer.

Reference link:

[1]https://www.bilibili.com/video/BV1yj41167Xd/?

[2]https://forums.spacebattles.com/threads/claims-of-room-temperature-and-ambient-pressure-superconductor.1106083/page-11?

[3]https://www.zhihu.com/question/614849582

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