The topic "Improvement of Relaxor Ferroelectric Thin Film Materials" can be said to be the most difficult applied scientific research topic Qin Ke has encountered so far, bar none.

Even with EDA design and the original operating system, he didn't find it too difficult, because those two topics had the main ideas given by the system as the correct path guide, just like he was going somewhere and had it in his hand.

There is a map with the route marked, but all that is missing is to drive the car yourself and slowly follow the route to your destination.

But this topic of "Improvement of Relaxor Ferroelectric Thin Film Materials" is different.

Qin Ke only knew the approximate correct direction, but the way to go and the places he had to pass through were all a blur.

Because the difficulty of this topic is not the experimental operation at all. After all, Qin Ke and Ning Qingyun can master the specific experimental operation in one day. Even graduate students who are not as talented as them can only spend a week at most to become familiar with the operation of the laboratory.

All the equipment needed is available.

What is really difficult is that there are so many options to choose from, such as improving the shape and thickness. What kind of thickness and shape can solve the loss problem caused by the electrical domain flipping energy barrier? The thickness problem must be accurate to the micron level.

The shapes are even more varied and of numerous types.

Another example is the improvement of doping with special elements. There are too many special elements to choose from. The metal elements in the element list include gold, silver, copper, iron, tin, platinum, mercury, aluminum, zinc, titanium, tungsten, and lead.

, 90 kinds such as nickel, most metal elements can generate oxides, and oxides are divided into basic oxides, acidic oxides, peroxides, superoxides, amphoteric oxides, not to mention a variety of metals

The scheme of simultaneous doping of elements.

And unlike "all roads lead to Rome", there is only one road leading to the optimal end point of this subject. The rest of the roads are either wrong, or they can only fail to reach the optimal end point and can only barely reach a point in the middle.

.

Qin Ke read through the detailed information on the topic and knew that Professor He Liangfu had relied on theoretical deductions and asked postdoctoral fellow Huo Guangxin to lead his team to test hundreds of possible solutions, but still failed to solve this problem. Why?

Professor Liang Fu even overturned the previous results and reset the experimental ideas from the beginning, but in the end he was still stuck on the loss problem caused by the electric domain flipping energy barrier, and the energy storage density and energy storage efficiency were never reached.

Qualification line required by the subject.

In other words, the current subject has only moved some way towards the optimal end point, but it is still far from the halfway point, let alone the optimal end point.

Qin Ke let out a breath and slowly closed the laptop.

After reading all the subject materials for the fifth time, he found no new inspiration.

In the morning, he completed the first version of mathematical modeling through experimental data and existing theoretical information on the topic, and programmed it through low light, but the effect was not ideal.

The problem just mentioned involves too many possibilities, covering both physical materials science and chemical materials science. However, thousands of experimental data seem too thin and insignificant in the face of such astronomical number of choice possibilities.

What's more, there are many conflicting theories and schools of thought regarding materials science, which makes this subject even more difficult.

But this not only did not make Qin Ke feel discouraged, but instead aroused his fighting spirit.

The consumption must be reduced by at least 20% to reach the qualified line, a full 20%... It is difficult, challenging, and interesting!

Qin Ke turned around and asked Ning Qingyun next to him: "Jun'er, do you have any good suggestions?"

Ning Qingyun has been reading some molecular-related theories all morning, such as molecular covalent bond theory, hybrid orbital theory, molecular orbital theory, etc. These are all related to the topic. Qin Ke has taught her through "thinking resonance"

, she was looking through theoretical materials mainly to try to see if she could improve the first version of the mathematical model that Qin Ke wrote in the morning.

The girl fiddled with her hair on her temples, her eyes still vaguely retaining the charm from last night, but her expression was extremely serious.

This is Ning Qingyun who has completely entered the state of scientific research.

"Judging from our attempts this morning, it is not feasible to build a large mathematical model to seek breakthroughs based on the current experimental data. I suggest that we build several small models first to break through the difficulties one by one!"

Qin Ke thought it made sense. After establishing a small model, the current experimental data was relatively effective.

It seems that you should not think about resolving the battle in a few days, but be prepared for a protracted battle. If you can finish it within a month, it will be a great success.

"Okay, let's refine the first direction into two mathematical models, and each of us will be responsible for one."

Qin Ke asked Ning Qingyun to be responsible for establishing a mathematical model in the direction of "improving from the aspect of thickness", while he specialized in the mathematical model in the direction of "improving from the aspect of shape". Relatively speaking, the former is easier, while the latter is more difficult.

It is easy, but only in comparison. Judging from the current experimental data, there is no simple linear relationship between the properties of relaxor ferroelectric thin film materials and their thickness, but an irregular curve change relationship, and

The insufficient "granularity" of the experimental samples makes this curve change relationship even more messy, and it is not easy to establish a data model.

Fortunately, Ning Qingyun is very patient and has a solid foundation in mathematics. She writes calculations around the experimental data and explores the correlations in the data.

Qin Ke's style is more direct. He directly goes through all the experimental data related to "shape change" in his mind, repeatedly forms chart trends, and then combines professional-level physics knowledge to screen.

The "shape" mentioned in this topic is not as superficial as cutting the relaxor ferroelectric thin film material into a rectangle, circle or triangle, but refers to its internal structure, especially the heterostructure.

Different internal structures will lead to different heterojunction peak barrier heights, which will affect the current density, carrier concentration and diffusion current flow direction, and even produce drift current and tunnel current. In addition, the constants of the lattice must also be considered.

And thermal expansion coefficient, as well as the interface state of dangling bonds and defective energy levels in the forbidden band...the above factors will all intensify or reduce the loss caused by the electric domain flipping energy barrier to a greater or lesser extent.

This chapter is not over yet, please click on the next page to continue reading! Qin Ke closed his eyes and meditated for nearly an hour before writing and starting to calculate.

"^(3/)^(-1/2)]......"

He wrote nearly forty pages of manuscript paper and finally came to a conclusion. Based on this conclusion, he established a new mathematical model, converted it into a program through the glimmer of light, and conducted deductions...

When Qin Ke stood up and rubbed his sore eyes, he realized that the sky outside the window was full of red clouds and the sun was setting in the west.

Qin Xiaoke, who was sitting on the lunch break bed in the study practicing painting, had fallen asleep at some point. Ning Qingyun was gently covering her with the air-conditioned quilt.

Seeing Qin Ke's relaxed expression, Ning Qingyun blinked her beautiful eyes and asked, "Have you got your mathematical model?"

"Basically, it's out. The details still need to be improved, but now we can let our lab partners try experiments to verify the deduction results. What about you?"

"I'm pretty much the same. Based on the mathematical model I established, I deduced that the most appropriate thickness values ​​should be between .45μm and .67μm. However, it still needs to be continuously optimized through experiments to finally get the most accurate range possible.

"By the way, come and take a look at this." Ning Qingyun said, stretching out her hand and pulling Qin Ke to sit on the edge of the bed.

Qin Kezheng was a little surprised at Xiao Baicai's boldness, but saw her smiling and pointing to the easel on the bed.

Qin Ke looked along her white and tender little fingers and saw a sketch on the easel. Two figures of a boy and a girl sitting side by side, each doing calculations, jumped onto the painting. Both of them looked serious and focused, their hair was beautiful.

The girl with her hair down was subconsciously fiddling with her hair with her fingers, her beautiful eyebrows slightly furrowed, and the pen in her right hand still hanging in the air, as if she was thinking about a difficult problem.

The boy's hair was a little messy, but his eyes were sharp and bright, he was holding a pen and writing mathematical formulas quickly.

This is exactly the picture of Qin Ke and Ning Qingyun sitting at the desk together in the afternoon to study a topic. The expressions of the characters are extremely vivid and can be said to be lifelike. Even if Qin Ke is not good at painting and has no artistic ability, he can still see it.

This painting is indeed of a very high standard.

"Awesome, this little girl, I knew she was very talented in painting, and she often taught herself painting, but I never thought she could reach such a level." Qin Ke looked at the little girl sleeping soundly on the nap bed, and thought in his heart

There is a faint sense of pride.

"Xiao Ke works very hard. In addition to normal homework studies, she also looks for various videos on the Internet to learn painting." Ning Qingyun stretched out her hand and stroked Qin Xiaoke's hair with pity: "She once told me

, when she was young, she was ignorant and always thought that she could rely on her brother to support her for the rest of her life. But now she knows that her brother will get married and start a family when she grows up. She cannot become a burden to her brother. She must work hard to support herself independently in the future...

…”

Qin Ke was stunned.

In the past two or three years, he really didn't care enough about his sister. At most, he just watched her study, but never bothered to talk to her. He didn't even know that the little girl had such thoughts.

No wonder Qin Xiaoke has been studying harder in the past year and rarely plays games...

Just like today, it was obviously a holiday and Qin Xiaoke could play games, go to the movies or go shopping, but she chose to stay in the study and practice sketching.

For some reason, Qin Ke's nose felt a little sore when he thought of Qin Xiaoke practicing painting alone in his room.

Maybe he was so used to the little sister who lay flat on her back, but suddenly and inadvertently discovered that she had grown up and was still working hard to think about her family. I felt relieved and reluctant to let go?

"I'm going to cook." Qin Ke stood up to leave. Ning Qingyun followed him, pursed her lips and chuckled: "Do you want to treat Xiaoke to a delicious dinner?"

Qin Ke did have such thoughts, but he said stubbornly: "No, it's already dinner time."

"I found that you are actually a bit arrogant. Just like your grandfather, you obviously want to be good to your family, but you are unwilling to express it honestly. Qin Xiaoke, you are actually quite cute in this regard."

"Hey, Jun'er, your wings have become stronger recently and you have learned to tease your husband? Wasn't last night exciting enough?"

Ning Qingyun's face suddenly turned red. She glanced at Qin Xiaoke and saw that she was still sleeping soundly and probably didn't hear her. Then she breathed a sigh of relief and rolled her eyes at Qin Ke: "Rogue, don't say this in front of Xiaoke."

"It's late. When you went to take a shower in the morning, the little girl woke up and sneaked to the kitchen to ask me if I ate you last night. I told you honestly..."

"Bad guy! How could you say this to Xiao Ke..." Ning Qingyun's ears turned red this time. No wonder today she always felt that Xiao Ke was secretly observing her with a smile, and even called her sweetly, "Hello, sister-in-law."

",I see!

"Okay, okay, she's not a child anymore. Children know a lot these days... Let's cook. Do you want Jun'er to come with us?"

The girl turned her face away shyly and arrogantly: "I don't want to care about you anymore."

Qin Ke smiled and said, "How about I kiss you ten times as compensation? Come on, come on, the first time..."

"No...itchy...bad guy...well..."

…

Here, Qin Ke and Ning Qingyun are playing sweetly, preparing dinner together in the kitchen filled with the setting sun. The picture is full of life.

In Professor He's laboratory at Qingmu University, Professor He, Huo Xinguang and others were frowning and discussing the mathematical model deduction results just sent by Qin Ke and Ning Qingyun.

Huo Xinguang said distressedly: "It's strange enough that there are two thick and thin intervals. Qin Ke also said that the optimal heterojunction shape should be a mesh structure? We have tried three options for the mesh structure before, but the effect was not good.

Obviously. Could their mathematical model be wrong? After all, they also said in the email that the current mathematical model still has a lot of room for improvement and is not perfect enough."

Professor He Liangfu insisted: "First try a thickness of 0.48μm, coupled with Qin Ke's mesh structure. There are many differences between this mesh structure and our original plan, and the spacing has increased by nearly one-third.

."

This chapter is not finished yet, please click on the next page to continue reading the exciting content! The boss spoke, and all the team members hurriedly got busy.
To be continued...