Start as a top student and move towards the stars and the sea

When the Spring Festival holiday was coming to an end, Ning Chen was also thinking about whether to go back to Shengzhou first or go directly to Yanjing.

At present, Ning Chen has not decided on a new research topic. Even if he returns to Shengzhou, he will mainly conduct some self-study.

But because it was still during the winter vacation, Ning Chen went to Yanjing University and there were no courses to attend.

While Ning Chen was struggling with these issues, Ning Chen received a message from Tao Wei.

In the message, Tao Wei said that he had established a new project team and invited Ning Chen to come over and participate in the project when he had time.

Ning Chen was worried that he had nothing to do, and Tao Wei's invitation just helped Ning Chen find a new direction.

Ning Chen immediately replied to the message, saying that he would go to the Chinese Academy of Sciences as soon as possible to participate in the project.

On the seventh day of the Lunar New Year, Ning Chen boarded a plane to Yanjing.

When they arrived at the Chinese Academy of Sciences, Luo Fang first helped Ning Chen arrange a dormitory, and then briefly explained the project arrangements to Ning Chen.

Because the project team has just been established and the New Year has just passed, some project team members are still in their hometowns and the project is not expected to officially start until the day after tomorrow.

Ning Chen was not in a hurry to start the project right away. In the past two days, he could make more preparations so that he could get into the mood faster after the project started.

In the two days before the start of the project, Ning Chen inquired about a lot of information about iron-based superconducting wire strips. He also came to the laboratory for inspection in advance and exchanged more information about the project with Tao Wei and others.

This gave Ning Chen a basic understanding of the entire project and was ready to start the project.

Two days later, all members of the project team had arrived, and Tao Wei organized everyone to come to the laboratory for a project meeting.

This time, there are more than ten teachers and students participating in the project. Except for Ning Chen, they are all members of Tao Wei’s experimental group at the Chinese Academy of Sciences.

Although Ning Chen is the youngest among them, everyone respects Ning Chen very much and does not have any contempt for Ning Chen because of his age.

After all, Ning Chen has published so many papers in "Nature", and in addition to materials science, Ning Chen also has high attainments in mathematics.

For such an outstanding young man, there is nothing that can express their feelings except admiration.

After Tao Wei introduced Ning Chen to everyone, he talked about the experimental plan for this subject.

The purpose of the project team's experiment this time is to study the preparation of wire strips for various iron-based superconductors.

Because according to Tao Wei's analysis, iron-based superconductors have a lot of application space and are more suitable for wire and strip processing.

“As more and more iron-based superconductors are discovered and the critical temperature of iron-based superconductors is refreshed, research on iron-based superconductor wire strips has become urgent.

In the future, superconducting materials will have certain application space in superconducting energy storage devices, large-scale power transmission and distribution, superconducting generators, super strong magnets, maglev trains, transformers and other fields.

In this project, we are going to study the preparation of wire strips of these iron-based superconductors. "

Ning Chen looked at the several superconductors selected by Tao Wei and noticed that some of them were the iron-based superconductors discovered by Ning Chen.

Ning Chen soon wanted to understand why Tao Wei chose these iron-based superconductors for the research of superconducting wire strips.

In addition to the higher superconducting critical temperatures of these iron-based superconductors, the properties of these iron-based superconductors are also relatively stable.

Some superconductors, because of their poor connectivity, do not have much application value even if the superconducting critical temperature is very high. They are more of theoretical research significance.

It can be seen that Tao Wei has indeed carefully studied Ning Chen's papers before, and has a very deep understanding of these iron-based superconductors.

Perhaps before this, Tao Wei and others have completed the reproduction of the preparation of these iron-based superconductors.

On the day the project opening meeting ended, the project work officially began.

After the experiment started, Ning Chen quickly integrated into the laboratory and started the experiment with everyone.

Ning Chen had to admit that the scientific research atmosphere of the Chinese Academy of Sciences was really good.

From top to bottom, whether it is professors, researchers, or students in the experimental group, there is a strong scientific research motivation.

Ning Chen couldn't describe this feeling well, and when Shuimu and Yan were in college, Ning Chen never had the same feeling.

Ning Chen felt that perhaps it was the special nature of the Chinese Academy of Sciences that created this unique scientific research atmosphere.

As the experiment progressed, Ning Chen's views on the project team changed somewhat.

Originally, Ning Chen thought that he would take on the main guidance work in the synthesis of iron-based superconductors.

This is not because Ning Chen is self-righteous, but because the synthesis of these superconductors was originally developed by Ning Chen.

Even if the synthesis is carried out according to the method in the paper, it is very difficult to perfectly synthesize an ideal superconducting material.

However, what Ning Chen did not expect was that when synthesizing these iron-based superconductors, the project team members only discussed some key parts with Ning Chen, and the main work was completed by everyone together.

It was the first time for Ning Chen to participate in a project team with a large number of members, and he was amazed by the teamwork ability of the entire project team.

…

As the experiment progressed, the project made some breakthroughs, and of course encountered various problems.

The first major problem encountered by the project team was the processing of some iron-based superconductors containing K and As elements.

Because K element and As element have higher chemical activity and higher melting point.

At high temperatures, it is easy to cause the reaction and volatilization of elements, causing the superconducting performance of the superconducting system to be affected.

Similar problems also occur in iron-based superconductors containing F elements.

The F element is easily burned at high temperatures, making it very difficult for iron-based superconductors containing F element to form phases.

In order to solve these problems, Tao Wei proposed to change the element ratio of the superconducting system and add excess K, As, F and other elements into it.

During the laboratory meeting, Tao Wei explained the reasons why he proposed this idea.

"According to the microstructure of the material obtained by scanning electron microscopy, we can see that the loss of superconducting elements including K, As, and F leads to the formation of a second phase in the superconducting wire strip.

This leads to changes in their composition and also to inhomogeneities in the microstructure.

Excessive addition of these elements can compensate for the loss of these elements. "

After listening to Tao Wei's thoughts, everyone agreed with this proposal.

Ning Chen also felt that this was the only way to solve the problem that he could think of at the moment.

Of course, Ning Chen also knows that in actual operations, the specific amount of excess elements to be added needs to be explored through a large number of experiments.

Having determined the direction to solve this problem, the project team restarted the experiment.

At the beginning, because the proportion of new elements was not controlled accurately enough, the newly synthesized substances still did not have the ideal microstructure.

However, as the experiment progressed, the project team gradually mastered the ratio of elements, and the newly synthesized substances became more and more ideal.

Through element compensation, the phase formation problem of iron-based superconductors containing As and F elements has been successfully solved.

However, the phase formation problem of iron-based superconductors containing K element has not been completely solved.

Tao Wei believes that the reason for this is that the element ratio has not been adjusted properly, and he continues to try to conduct more extensive and detailed experiments in this way.

To everyone's disappointment, after conducting extensive experiments, this problem still occurs.

At this time, Tao Wei was also hesitating whether to give up research on this type of K-containing iron-based superconductors.

After all, not all iron-based superconductors are suitable for processing into wire strips. The project team is also very tight on time, and there is no need to waste too much time on these materials with very little application value.

Ning Chen did not give up research on this material immediately, and kept thinking about possible solutions to the problem.

In order to allow himself to understand the problems of this material in more detail, Ning Chen used a transmission electron microscope to conduct more detailed tests on this material.

Looking at the material characterization images obtained from the transmission electron microscope, Ning Chen frowned and began to think.

Because Ning Chen discovered that lattice distortion occurred in this iron-based superconductor containing K, which caused the material to generate a large number of dislocations.