Progress ｜ Infinite nickel -based superconducting thin film TC is increased to more than 30 K under pressure

Among all the superconductors discovered so far, the high temperature superconductors of copper oxide to maintain the highest record of superconducting critical temperature (C) under the normal pressure (C). Its unconventional superconducting micro mechanism is still the most challenging scientific issue in the field of cingling physics. one. As the nearest neighbor Ni Ni in the element cycle table, the theory pointed out as early as the early 1990s that the nickel oxide of the unlimited structure has a crystal structure and electronic structure that has similar crystal structure and electronic configuration because the high -temperature superconductors of copper oxides of copper oxide is considered to be considered to be considered to be considered It is a potential high -temperature superconducting system. However, more than 30 years of experimental progress has been slow, and people have not found superconducting in polycrystalline, single crystal and film samples of unlimited nickel oxides. Until 2019, the HAROLD HWANG research team of Stanford University in the United States adopted the TopotActic Reduction to restore the extension of the extension of the extension of the oligozoic ND1-XSRXNIO3 thin film the ND1-XSRXNIO2 thin film of the infinite layer of structure, and it was among them. For the first time, the superconductivity of C = 9-15 K has set off a boom in the research of nickel-based superconductors [Nature 572, 624 (2019)]. This is an important progress in the field of superconducting research in recent years. It immediately attracted a large number of subsequent theoretical and experimental research. For the latest progress, please refer to the summary article [Chinese science: Physical mechanics astronomy 51, 047405 (2021); The Innovation 3, 100202 (100202 ( 2022)]. However, due to the harsh preparation conditions of the unlimited nickel -based superconducting thin film, only a few internationally internationally internationally can prepare a thin film sample with superconducting transformation in the world. One of the main difficulties. Although the subsequent studies reported the rare earthy-based superconductors mixed with alkaline soil metal, such as LA1-X (CA/SR) XNIO2 and PR1-XSRXNIO2, the maximum C did not exceed 15K, which was far lower than C-temperature superconductors C. Essence How to further improve the C and the similarities and differences between the high -temperature superconductors of the copper oxide oxide and the high -temperature superconductor of the copper -based superconductor.

In response to the above issues, multiple research teams from the Institute of Physics of the Chinese Academy of Sciences/Beijing Ningxin Physics National Research Center carried out experimental research on nickel -based superconductors: the team of Kim Kuijuan, a group of Jin Kuijuan in the Key Laboratory of Light Physics, overcome multiple sample preparation. Successfully grows high-quality unlimited PR0.82SR0.18NIO2 (PSNO) superconducting thin film. Experimental research lays the foundation. In addition, Zhu Zhihai's special researcher and Zhou Xingjiang researcher team of the National Key Laboratory SC07 successfully prepared ND0.8SR0.2NIO2 superconducting film [chin. Phys. Lett. 38, 077401 (2021)]. Recently, Wang Ningning, Chen Keyu, and associate researcher of Sun Jianping and researcher Cheng Jinguang, a doctoral student in the Extra Group EX6 group EX6 group EX6 group, adopted the high -pressure low temperature measurement device of the six -sided anvil, high static water pressure at 12.1 GPA, and the minimum mild at the minimum mild at 1.5 K. 8.5 In the comprehensive extreme environment of T magnetic fields, a detailed high -pressure magnetic electrical transportation properties were carried out on the high -quality PSNO thin film, and it was found that its superconductant transformation temperature increased with the pressure and no signs of saturation. When 12.1 GPA, ConSet Stepping to about 31 k, this indicates that the n nickel -based superconductor C can be further improved.

Because the unlimited nickel -based superconducting thin film prepared by the soft chemistry regulation reaction is very fragile, it must be obtained in a very good static water pressure environment to obtain the pressure effect of its superconducting transition. Therefore, the six -sided anvil device that can provide a good static water pressure environment plays a key role in obtaining the pressure effect of the PSNO superconducting thin film. Figure 2 shows the high -voltage resistivity data of two PSNO film samples using two different liquid pressure -passing medium tests. It can be seen from the figure that the superconductant transformation temperature increases monotonous with the pressure, and it can reach 31 k at 12.1 GPA. Figure 3 shows the temperature-pressure phase diagram determined according to the measurement results under multiple samples. The pressure coefficient that can be determined from the figure is d/d ≈ 1 k/gpa, and there is no sign of saturation within the research pressure range of the research. This means that it can rise further under higher pressure. In order to reveal the origin of the PSNO film superconducting electrical positive pressure effect, they also tested the resistivity curve of different pressures and magnetic fields, and analyzed the critical criticality through the Ginzburg-Langdao formula and Werthamer-Hohenberg (WHH) formula. Fields with the change of pressure, as shown in Figure 4. The results show that the effective quality of electrons at high pressure is reduced, which means that the electronic association is weakened with pressure; and according to the recent results of the theoretical research on unlimited nickel -based superconducting film, it has an anti -correlation with the electronic association. The experimental results of this study are in line with. In addition, they also summarized the relationship between the corresponding doping of the infinite nickel -based superconducting thin film that has been reported. As shown in Figure 4 (C), it can be seen that it has gradually increased as the C axis decreases and gradually increases. In this way, the continuous decrease in the lower axis of high pressure can also explain the law of rising with the monotonous pressure. The above results provide important references to further improve the nickel -based superconductors and build the theoretical model and understand its superconducting mechanism. Related results were recently published in Nature Communications 13, 4367 (2022). Doctoral students Wang Ningning, Yang Mingwei and Yang Zhen were the first authors of the dissertation, and Sun Jianping, Jin Kuijuan and Cheng Jinguang communicated the author of the paper. Participating in this work also includes researcher Dong Xiaoli, Zhang Hua, an associate researcher of Zhang Hua, Zhu Zhihai special researcher, researcher Gulin, associate researcher of the advanced material and structural analysis laboratory, and Professor Yoshiya Uwatoko in the University of Tokyo, Japan. This work is supported by the support of the Ministry of Science and Technology's key R & D plans, the National Natural Science Foundation of China, the Beijing Nature Fund Commission, and the Chinese Academy of Sciences B. -category B and other projects.

[1] N. N. Wang, M. W. Yang, Z. Yang, K. Y. Chen, H. ZHANG, Q. H. ZHANG, Z. H. Zhu, Y. UWatoko, L. Gu, x. L. Dong, J. J. JIN and J.-G. Cheng; "Pressure-induced Monotonic Enhancement of to Over 30K in SuperConductuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctuctational PRSRNIO Thin Films";. 13, 4367 (2022).

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Figure 1. Infinite PRSRNIO film superconductors XRD, TEM and resistivity data

Figure 2. The resistivity of unlimited PRSRNIO superconducting thin film

Figure 3. The temperature of the unlimited PRSRNIO superconducting film-pressure phase diagram

Figure 4. Infinite PRSRNIO superconducting thin film and the relationship between the wheelbase of different nickel -based superconducting thin membranes and superconducting

Edit: yellow water machine

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