Great Country Academician

In the meeting room, Xu Chuan took the notebook from Fan Pengyue and flipped through the data inside.

The researcher who explored the ultra-low temperature superconducting copper-carbon-silver composite material is called 'Song Wenbo', a professor dug from Wuli University, whose main research field was material chemistry.

This time, Professor Song was able to explore ultra-low temperature superconducting materials, half of which depended on experience and half by luck.

He did not take the powder metallurgy method of traditional materials science, nor did he take the high-temperature and high-pressure synthesis method commonly used to study superconductor materials to study copper-carbon-silver composite superconducting materials, but took the development route of nanomaterial preparation and molecular modification.

He first prepared copper-carbon-silver composite materials by nano means, and then manipulated and adjusted the fine atomic structure by vapor deposition.

Compared with the conventional powder metallurgy method for preparing copper-carbon-silver composite materials, this new method solves the problem that the interface between copper and carbon is not firmly bonded and there are a large number of holes in the composite material.

Compared with the high-temperature and high-pressure superconductor research method, it also avoids the disadvantages of copper atoms and carbon atoms that do not react even at high temperatures and have extremely poor wettability.

It has to be said that Wuli University, which ranks among the top five domestic universities in the field of materials research, still has some skills.

A professor of material chemistry who is above average and not top-notch, has sufficient experience and coping methods in conceiving the research and development of new materials.

If there is a disadvantage, it is that in the process of two-dimensional film deposition, the use of binders, even if only a small amount of binders, destroys the purity of the copper-carbon-silver composite material itself to a certain extent.

This not only means that it needs lower temperatures to make this thin-film material reach the superconducting energy gap. It also means that the performance of the material itself is greatly reduced.

"It's interesting. Call this Professor Song and ask him if he has time now. If so, please ask him to come over. I have some questions and I want to consult him."

After flipping through the information on the computer, Xu Chuan raised his head with interest, tapped his fingers on the table, and said to Fan Pengyue.

To be honest, the value of this ultra-low temperature superconducting copper-carbon-silver composite material itself is not that great.

First of all, the material studied by Professor Song is a two-dimensional thin film structure, and it is still very difficult to process it into wires or other shapes of superconducting materials.

The second is to achieve superconductivity at a temperature of 43.5K (about -230 degrees Celsius), which has already existed outside.

For example, the Large Intense Particle Collider at CERN.

Accelerating particles requires extremely strong magnetic fields, and strong magnetic fields require superconducting materials to reach their limits.

The LHC particle collider uses a niobium-tin alloy. After being cooled by liquid helium, this material has been able to superconduct in a normal pressure environment and can be mass-produced.

Apart from low-temperature superconductivity, high-temperature superconductivity has actually been studied for a long time.

As early as 1987, scientists from countries such as China, the United States, and small island countries all discovered that 'barium-yttrium-copper oxide' possessed Tc in the liquid nitrogen temperature range, and thus had superconductivity.

(Tc refers to the critical temperature, which is the temperature at which the material changes from a normal state to a superconducting state. For example, mercury, when the temperature is slightly lower than 4.2K, the resistance of mercury disappears suddenly, showing a superconducting state, so the Tc of mercury is 4.2K, about minus 268.95 degrees Celsius.)

However, limited by the fact that copper oxide superconductors are like very brittle ceramic materials, you cannot pull them into thin wires, coupled with high manufacturing costs, and problems such as failure due to slight impurity contamination, high-temperature superconductors have not been able to be applied in industry. .

Therefore, the temperature superconductivity of 43.5K alone does not have much practical value.

Not only does it need to be frozen in liquid helium to be superconducting, but it cannot be produced industrially.

However, he found some very interesting things in this material.

If you can figure it out, maybe you can explain the superconducting principle of high-temperature superconducting materials from another angle.

To know the basic principle of high-temperature superconductivity of superconducting materials, let alone the beginning of 2020, even after more than ten years, no real explanation has been found in later generations.

Even if he researched room-temperature superconducting materials in later generations, he failed to explain the reason for the existence of room-temperature high-temperature superconductors.

In other fields, this is almost impossible or extremely difficult.

Theory has not been formed, how can the actual results be made?

However, in the field of materials science, it is not uncommon for experiments to come out by accident without theory.

Many materials used in the society today actually have results first, and then research results to obtain theories.

If the superconducting basis of high-temperature ultra-temperature superconducting materials can be explained clearly, it will definitely be a huge improvement for the development of superconducting materials.

Fan Pengyue nodded, took out his mobile phone from his pocket and made a call, asked about it and then hung up.

Not long after, there was a knock on the door outside the meeting room.

Xu Chuan said, "Please come in."

Immediately, the door opened, and a middle-aged man with gold-rimmed glasses walked in.

"Boss Fan, are you looking for me?"

Song Wenbo came in and asked, but his eyes fell on Xu Chuan who was sitting at the desk.

He was involuntarily stunned by the familiar figure, and asked doubtfully, "Are you Academician Xu?"

When the Chuanhai Materials Research Institute poached him, he knew that the real master behind this laboratory was the famous Professor Xu Chuanxu.

He recognized Xu Chuan, but he doubted if it was real.

Because since joining the company, let alone him, most people in Chuanhai Materials Research Institute have never met this real boss.

So even if I saw a real person, I would have some doubts about whether I was wrong.

On the opposite side, Fan Pengyue looked at Xu Chuan, and said with a smile: "You said you, you have been the shopkeeper for a long time, and the company employees don't know you anymore."

Xu Chuan ignored Fan Pengyue. He smiled at Song Bai and said, "It's me. Professor Song, please sit down. I'm here this time because I have some questions to ask."

Song Wenbo walked over quickly, and asked nervously, "Say it."

Although he is much older than the one in front of him, there is a huge difference between the two in terms of knowledge and status.

There are only four giants at the academician level in the entire Wuli University. Although he has met and communicated with them, it is the first time that such a giant academician has become his immediate boss.

And this is still in a private company, not in a school. The leader has more power over his subordinates, and the pressure on him is even greater.

Of course, if the opportunity is seized, especially the Chuanhai Materials Research Institute, which has just begun to expand, the road ahead will be bright.

He is almost fifty this year, and his academic level is still there. Although he is not weak, he is not top-notch, so his prospects for promotion in Wuli have almost reached the peak.

And change to a new environment, maybe you can go a little further. This is also the reason why he was able to be recruited, not only for money, but also for the hope of promotion.

Xu Chuan didn't pay too much attention to these things. He connected the computer on his desk to a virtual projection, and opened the research data of ultra-low temperature superconducting copper-carbon-silver composite materials.

"I have some questions about the ultra-low temperature superconducting copper-carbon-silver composite material you have developed."

"First of all, it is about the X-ray diffraction analysis data. Through X-ray research, the sample has a structural phase transition process from orthorhombic crystal to tetragonal crystal when x≈0.04, and the volume of the original cell increases with the increase of copper components."

"The zero-resistance temperature measured by the R-T curve will drop rapidly with the increase of the copper component, until the temperature drops below 50K, the zero-resistance temperature decreases with the increase of X, and there is no sudden change at the structural phase transition point."

"What do you think about this?"

There is no analytical answer to this question in the data given to him by Fan Pengyue, which means that the current analysis results have not been made.

If you want to know, it is the fastest to directly ask the person in charge of the experiment.

Song Wenbo thought for a while, and said: "According to my speculation, this should be the effect of the doping of elements such as the adhesive on the copper-carbon-silver composite material. The electronic doping of the adhesive will cause its lattice coefficient to change. Variety."

"When I was at Wuli University, I studied the effect of hole doping on the electronic structure. Under the external pressure system, the magnetism is gradually suppressed by the many-body effect of the electrons in the strongly correlated system."

"This may be the reason why the zero resistance temperature decreases with the increase of X after the temperature drops below 50K, and there is no sudden change at the structural phase transition point."

Listening to Song Wenbai's explanation, Xu Chuan tapped his fingers on the table one after another, and fell into deep thought.

Does hole doping affect the electronic structure and lattice coefficient?

If he remembers correctly, when he was researching copper-carbon-silver composite superconducting materials in his previous life, what he first studied was not copper-carbon-silver composite materials, but copper-silver oxide nanomaterials.

Because oxide materials are recognized as the most promising to break through the limit of high-temperature superconductivity.

Later, the reason why he replaced oxygen with carbon was actually caused by an accidental experiment.

The reason why oxide superconductors have become mainstream is not only because they can break the limit of ultra-low temperature superconductivity, but also because copper oxide high-temperature superconductors also show many exotic properties.

For example, its superconducting phase has d-wave pairing symmetry, which is different from the s-wave symmetry of conventional superconductors;

Another example is that the parent material has an antiferromagnetic Mott insulating phase, and there are pseudo-gap and Fermi arcs in the under-doped region.

Today, Song Wenbai's words brought him a new hint of inspiration, and he may be able to get the answer to the key that he has not figured out before.

If the original copper oxide silver nanomaterial is regarded as a superconductor, perhaps the carbon accidentally doped into the original material may be the key to breaking the Tc critical temperature.

Perhaps, he can find the formation mechanism of cuprate high-temperature superconductor superconductivity.

If successful, this will definitely be the biggest breakthrough in history for high-temperature superconducting materials!

And with this set of theories, he can naturally develop superconducting materials at the fastest speed.

It's just that now he needs more data and information to verify his thoughts!

PS: Make up the second chapter of yesterday, ask for a monthly pass