I really just want to be a scholar

Chapter 502 Charge towards scientific research topics!

The subject of "Improvement of relaxor ferroelectric thin film materials" can be said to be the most difficult applied scientific research subject that Qin Ke has encountered so far, not one of them.

Even the EDA design subject in his hand and the original operating system subject, he didn't find it too difficult, because those two subjects had the main ideas given by the system as the correct road guidance, just like he was going to a certain place, I have a map with the route marked in my hand again, all I need is to drive in person and slowly follow the route to the destination.

But this topic of "improvement of relaxor ferroelectric thin film materials" is different.

Qin Ke only knew the approximate correct direction, but it was a blur of how to go and where to pass.

The subject of "Improvement of Relaxor Ferroelectric Thin Film Materials" is the same as other scientific research projects. It is based on theory, constantly experimenting, trial and error, summing up experience and re-proposing new hypotheses and guesses, which are verified by experiments again... The experiment is in which plays a key role.But the difficulty of this subject is not the experimental operation. After all, Qin Ke and Ning Qingyun can master the specific experimental operation in a day. Even graduate students who are not as talented as the two of them can spend at most a week to become familiar with the requirements of the experimental operation. all the equipment.

What is really difficult is that there are too many options to choose from, such as improving the thickness of the shape. What kind of thickness and shape can solve the loss problem caused by the electric domain switching energy barrier?The question of thickness has to be accurate to the micron level, and the shape is even more varied and varied.

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. , nickel and other 90 kinds, most metal elements can form oxides, and oxides are divided into basic oxides, acidic oxides, peroxides, superoxides, amphoteric oxides, not to mention a variety of metals A scheme for 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, and the rest of the roads are either wrong, or they cannot reach the optimal end point, and they can only barely reach a certain point in the middle. move on.

Qin Ke read the detailed information of the project, and knew that Professor He Liangfu had used the theoretical derivation to let the postdoctorate Huo Guangxin lead the team to test hundreds of the most possible solutions, but still failed to solve this difficulty. 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 caused by the domain flip energy barrier, and the energy storage density and energy storage efficiency were still not up to the mark. The passing line required by the subject.

In other words, the current subject has only moved a little way towards the optimal end point, but there is still a distance from the halfway passing point, let alone the optimal end point.

Qin Ke exhaled lightly, and slowly closed the laptop.

After reading all the project materials for the fifth time, he did not find any new inspiration.

In the morning, he completed the first version of mathematical modeling based on experimental data and existing theoretical information on the subject, and compiled it into a program through low light, but the actual deduction effect was not ideal.

As for the question just mentioned, there are too many possibilities involved, covering both physical materials science and chemical materials science, and the data of thousands of experiments seems too thin and insignificant in the face of this astronomical selection possibility.

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

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

It is necessary to reduce consumption by at least 20% to reach the qualified line, a full 20%... It is difficult, challenging, and interesting!
Qin Ke turned his head and asked Ning Qingyun next to him: "Jun'er, do you have any good suggestions?"

Ning Qingjun has been reading molecular-related theories all morning, such as molecular covalent bond theory, hybrid orbital theory, molecular orbital theory, etc. These are all related to the subject, and Qin Ke has taught her through "thinking resonance" She browsed through the theoretical materials mainly to try to improve the first version of the mathematical model written by Qin Kechen from different angles.

The girl fiddled with the hair on her sideburns, the charm of last night still vaguely remained in her eyes, but her expression had become extremely serious.

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

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

After thinking about it, Qin Ke also felt that it made sense. By building a small model, the current experimental data would be relatively effective.

It seems that I don't want to solve the battle in a few days, but I have to prepare for a protracted battle. If I can finish it within a month, it will be a big success.

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

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

It is easy to say, but it is only in comparison. According to the current experimental data, there is no simple linear relationship between the properties and thickness of relaxor ferroelectric thin film materials, but an irregular curve relationship, and The "granularity" of the experimental samples is insufficient, which makes the curve change relationship 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 and calculates around the experimental data, and discovers the connections in the data like a cocoon.

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 for screening.

The "shape" mentioned here is not as superficial as cutting the relaxor ferroelectric thin film material into a rectangle, circle and triangle, but refers to its internal structure, especially the shape formed by the combination of heterostructures.

Different internal structure shapes will lead to different peak barrier heights of heterojunctions, which will affect the current density and carrier concentration and the flow direction of diffusion current, and even generate drift current and tunnel current. In addition, the lattice structure must also be considered. Constants and coefficients of thermal expansion, and dangling bonds and interface states in gap-bound energy levels in the forbidden band...

The above-mentioned factors will more or less aggravate or reduce the loss caused by the electric domain switching energy barrier.

Qin Ke closed his eyes and meditated for nearly an hour before starting to write.

“反向电流J=Atrexp[BtrE^(3/2)(g2)(Vd-V)^(-1/2)]……”

He wrote nearly forty pages of manuscript paper, and finally came to a dozen conclusions, and based on these conclusions, he established a new mathematical model, converted it into a program through twilight, and deduced it...

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

Qin Xiaoke, who was sitting on the lunch break bed in the study and practicing drawing, fell asleep at some point, and Ning Qingyun was gently covering her with an air-conditioning quilt.

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

"Basically, it's done, and the details still need to be perfected, but it's time for the lab partners to try to do experiments to verify the deduction results. What about you?"

"I am also similar. According to the established mathematical model, the most suitable thickness value should be in the two intervals of 0.38μm-0.45μm and 0.59μm-0.67μm, but it needs to be continuously optimized through experiments, and finally concluded that As accurate as possible. By the way, let's take a look at this." Ning Qingyun stretched out his hand as he spoke, and pulled Qin Ke to sit on the side of the bed.

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

Qin Ke followed her white and tender little fingers and saw a sketchbook on the easel.On the top, two boys and girls sitting side by side, each doing calculations, are vividly drawn. Both of them look serious and focused.The girl with loose hair was subconsciously fingering the strands of her hair, her brows were slightly frowned, and the pen in her right hand was 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, and he was writing mathematical formulas quickly with a pen in his right hand.

This is exactly the picture of Qin Ke and Ning Qingyun sitting at the desk together in the afternoon and studying the topic. The expressions of the characters are very vivid and lifelike.Even if Qin Ke was not good at painting and had no artistic talent, he could tell that the painting was of a very high standard.

"Awesome, this little girl. I knew she had a great talent for painting before, and she often taught herself to paint. I didn't expect to be able to reach such a level." Qin Ke looked at the little girl who was sleeping soundly on the lunch break bed. There is a faint sense of pride.

"Xiaoke is working very hard. In addition to normal homework, I usually find various videos on the Internet to learn painting." Ning Qingyun reached out and stroked Qin Xiaoke's hair pitifully: "She once told me , I was not sensible when I was a child, and I always wanted to rely on my brother to support her for the rest of my life, but now I know that my brother will marry and start a new family when he grows up. She can't be a burden to her brother. She has to work hard so that she can 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 stared at her to study, but he never cared about talking with her. He didn't even know that the little girl had such thoughts.

It's no wonder that Qin Xiaoke has studied harder in the past year, and rarely played games...

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

For some reason, thinking of Qin Xiaoke practicing painting alone in the room, Qin Ke's nose felt a little sore.

Maybe it's because I'm too used to the little sister who is lying flat, and suddenly found out that she has grown up and is still working hard for the sake of her family. I feel relieved and sad?

"I'm going to cook." Qin Ke got up to leave, and Ning Qingyun followed, pursing his lips and chuckling: "Do you want to cook a delicious dinner as a reward for Xiao Ke?"

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 nice to your family, but you refuse to express it honestly. Qin Xiaoke, you are actually quite cute."

"Hey, Yun'er, your wings have hardened recently, and you have learned to tease your husband? Isn't it exciting enough to practice the Eastern Secret Code in the car last night?"

Ning Qingyun blushed immediately, and glanced at Qin Xiaoke. Seeing that she was still sleeping soundly, she should not have heard, so she breathed a sigh of relief, and rolled Qin Ke's eyes: "Rogue. Don't say such things in front of Xiaoke."

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

"Bad guy! How could you say such things to Xiao Ke..." Ning Qingyun's ears were red this time, no wonder today I always felt that Xiao Ke was always watching her secretly with a smile, and even called her sweetly, "Hello sister-in-law ",I see!

"Okay, okay, she's not a child anymore, kids know a lot these days... Cooking, cooking, do you want Yun'er to come together?"

The girl looked away shyly and arrogantly: "I don't want to talk to you anymore."

Qin Ke smiled: "Then I kiss you ten times as compensation, okay? Come on, come on, the first time..."

"Don't... itch... scoundrel... um..."

……

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

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

Huo Xinguang said distressedly: "It's strange enough to have two thick and thin intervals. Qin Ke also said that the optimal shape of heterojunction should be a network structure? We have tried three schemes for the network structure before, but none of them worked. 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."

Professor He Liangfu insisted: "First try the thickness of 0.48μm, coupled with Qin Ke's network structure. This network structure is quite different from our original plan, and the spacing has increased by nearly one-third. .”

The boss spoke, and all the team members hurried to work.

A few hours later, Huo Xinguang looked at the results of the report and swallowed in surprise: "It seems to be really useful... The loss has been reduced by about 5%! The difference from the qualified value is only 15%!"

Don't underestimate the 5%, they have been busy for more than a month, and they can't even reduce the loss by 1%!And these two young people have only officially joined the research team for two days, and they have delivered such amazing results!
"This computational material science, is it really so useful?" Everyone looked at each other in blank dismay, surprised and delighted and unbelievable.

Professor He's brows that were originally tightly locked were relaxed at this time, and he waved: "Okay, don't be surprised here, first send the experimental data back to Qin Ke and Ning Qingyun, they are still waiting for the data to optimize mathematics Model. Let's continue to discuss along this direction to see why this value and shape can work, and communicate the results of the discussion with Qin Ke and the others..."

Originally, the best way is to do all the numerical experiments in all intervals, but every time you do an experiment, you have to burn a lot of money. At present, the funds are a bit stretched. How can you afford so many experiments? Choose to strengthen theoretical research first, and get closer to the goal in the next experiment as much as possible.

……

The calendar was flipping page by page, Qin Ke and Ning Qingyun continued to attend classes during the day, and in their spare time they were simultaneously conducting research on EDA and "Improvement of Relaxor Ferroelectric Thin Film Materials".

The EDA project is only step-by-step, Qin Ke is mainly responsible for the compilation of module rules, Ning Qingyun is responsible for the advanced algorithms of the engineering library, and the specific details of the rest of the modules are very heavy, so Xu Qingyan and Luo Jian can only lead by dozens of senior experts. Engineers and technicians worked overtime and stayed up late to implement it, but the progress was relatively smooth.

The progress of the research on "Improvement of Relaxor Ferroelectric Thin Film Materials" has been fast and sometimes slow. Combined with the feedback from Professor He's laboratory, the two have been continuously optimizing the mathematical model. At present, Ning Qingjun has narrowed down the optimal thickness of the thin film material In the range of 0.59μm-0.62μm, Qinke’s network structure details have not made new breakthroughs. Although the overall loss has been reduced by 3%, there is still 12% of the distance from the target.

In the blink of an eye, it was July, and it was already the midsummer season. Qingmu University also ushered in the exam week. Qin Ke and Ning Qingyun could only concentrate on the final exam.

The exams for the two of them should be the most among the students in the school. In addition to the compulsory elective courses of the professional courses, the professional exams of the Department of Mathematics still have to be taken. This is the request of Academician Jiang and Professor Tian Jianlan. Get the basics as solid as possible.

Qin Xiaoke also started to get busy.

Qin Ke contacted Li Xiangxue's father, Li Shikun, and asked him to introduce a good art teacher. She was a female professor at the Beijing Academy of Fine Arts. Her surname was Mai. He is the dean of the Academy of Fine Arts in Yuanzhou, and he is also the leading artist in Huahai Province.

Naturally, Li Shikun's go-betweens are indispensable, and Qin Ke's own reputation has also played a lot of roles, not to mention that Qin Ke is willing to spend money and pay heavy gifts, and Qin Xiaoke's own talent is indeed excellent. After reading the sketch drawn by the little girl, they all expressed their willingness to accept Qin Xiaoke as their disciple.

Qin Xiaoke will learn painting from Professor Mai in Beijing during the summer vacation. After returning to Yuanzhou in September, he will study with Dean Ni from Yuanzhou.

Generally speaking, Qin Xiaoke's future painting path is paved.

After the busy exam week ended, the time entered mid-July, and the school also ushered in the summer vacation. College students began to leave school one after another, but Professor He's laboratory was still busy, and Qin Ke and Ning Qingyun also began to enter the real intensive scientific research During this period, we will make every effort to attack the subject of "improvement of relaxor ferroelectric thin film materials".

Qin Ke plans to finish Professor He's two projects within a month, because in August he needs to go to the old academician Wang Heng's side, and he will go back to Yuanzhou with Ning Qingyun, and maybe he will fly to the United States again ——The latter depends on whether the Cole Prize in Number Theory really falls on his head.

(End of this chapter)