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Electronic structure evolutions driven by oxygen vacancy in SrCoO3−x films

  • Jiali Zhao (赵佳丽)
  • Yi Luo (罗毅)
  • Jia-Ou Wang (王嘉鸥)
  • Haijie Qian (钱海杰)
  • Chen Liu (刘晨)
  • Xu He (何旭)
  • Qinghua Zhang (张庆华)
  • Heyi Huang (黄河意)
  • Bingbing Zhang (张兵兵)
  • Shunfang Li (李顺芳)
  • Erjia Guo (郭尔佳)
  • Chen Ge (葛琛)
  • Tieying Yang (杨铁莹)
  • Xiaolong Li (李晓龙)
  • Meng He (何萌)
  • Lin Gu (谷林)
  • Kui-Juan Jin (金奎娟)
  • Kurash Ibrahim (奎热西•依布拉欣)Email author
  • Haizhong Guo (郭海中)Email author
Articles

Abstract

Ionic defects, such as oxygen vacancies, play a crucial role in the magnetic and electronic states of transition metal oxides. Control of oxygen vacancy is beneficial to the technological applications, such as catalysis and energy conversion. Here, we investigate the electronic structure of SrCoO3−x as a function of oxygen content (x). We found that the hybridization extent between Co 3d and O 2p increased with the reduction of oxygen vacancies. The valence band maximum of SrCoO2.5+δ has a typical O 2p characteristic. With further increasing oxygen content, the Co ions transform from a high spin Co3+ to an intermediate spin Co4+, resulting in a transition of SrCoO3−x from insulator to metal. Our results on the electronic structure evolution with the oxygen vacancies in SrCoO3−x not only illustrate a spin state transition of Co ions, but also indicate a perspective application in catalysis and energy field.

Keywords

oxygen vacancies SrCoO3−x electronic structure evolution resonant photoemission spectra 

SrCoO3−x薄膜中氧空位引起的电子结构演变

摘要

离子缺陷, 比如氧空位, 在过渡金属氧化物的磁性和电子结构中起着至关重要的作用. 对氧空位进行调控广泛应用于催化和能量转换领域. 我们研究了SrCoO3−x的电子结构与氧含量x的关系, 发现随着氧空位含量的减少, Co 3d和O 2p之间的杂化增强. SrCoO2.5+δ的价带顶具有明显的O 2p特征. 随着氧含量的进一步增加, Co离子从高自旋的Co3+变成了中自旋的Co4+, 实现了绝缘体到金属的转变. 关于SrCoO3−x中氧空位引起电子结构演变的研究不仅展示了Co离子自旋的转变, 同时也为其在催化和能源领域的应用提供了理论支持.

Notes

Acknowledgements

This work was supported by the National Key R&D program of China (2016YFA0401002) and the National Natural Science Foundation of China (11574365, 11474349 and 11375228). The authors would like to thank BL14B1 beam line of Shanghai Synchrotron Radiation Facility for technique support.

References

  1. 1.
    Lu Z, Wu X, Jiang M, et al. Transition metal oxides/hydroxides nanoarrays for aqueous electrochemical energy storage systems. Sci China Mater, 2014, 57: 59–69CrossRefGoogle Scholar
  2. 2.
    Lu S, Zhuang Z. Electrocatalysts for hydrogen oxidation and evolution reactions. Sci China Mater, 2016, 59: 217–238CrossRefGoogle Scholar
  3. 3.
    Kalinin SV, Spaldin NA. Functional ion defects in transition metal oxides. Science, 2013, 341: 858–859CrossRefGoogle Scholar
  4. 4.
    Lan QQ, Zhang XJ, Shen X, et al. Tuning the magnetism of epitaxial cobalt oxide thin films by electron beam irradiation. Phys Rev Mater, 2017, 1: 024403CrossRefGoogle Scholar
  5. 5.
    Xie CK, Nie YF, Wells BO, et al. Magnetic phase separation in SrCoOx (2.5 ≤ x ≤ 3). Appl Phys Lett, 2011, 99: 052503CrossRefGoogle Scholar
  6. 6.
    Choi WS, Jeen H, Lee JH, et al. Reversal of the lattice structure in SrCoOx epitaxial thin films studied by real-time optical spectroscopy and first-principles calculations. Phys Rev Lett, 2013, 111: 097401CrossRefGoogle Scholar
  7. 7.
    Jeen H, Choi WS, Biegalski MD, et al. Reversible redox reactions in an epitaxially stabilized SrCoOx oxygen sponge. Nat Mater, 2013, 12: 1057–1063CrossRefGoogle Scholar
  8. 8.
    Jeen H, Choi WS, Freeland JW, et al. Topotactic phase transformation of the brownmillerite SrCoO2.5 to the perovskite SrCoO3−δ. Adv Mater, 2013, 25: 3651–3656CrossRefGoogle Scholar
  9. 9.
    Lee JH, Choi WS, Jeen H, et al. Strongly coupled magnetic and electronic transitions in multivalent strontium cobaltites. Sci Rep, 2017, 7: 16066CrossRefGoogle Scholar
  10. 10.
    Zhu ZH, Rueckert FJ, Budnick JI, et al. Distinct magnetic phases in structurally uniform SrCoO3−y. Phys Rev B, 2016, 93: 224412CrossRefGoogle Scholar
  11. 11.
    Hu S, Seidel J. Oxygen content modulation by nanoscale chemical and electrical patterning in epitaxial SrCoO3−δ(0<δ≤0.5) thin films. Nanotechnology, 2016, 27: 325301CrossRefGoogle Scholar
  12. 12.
    Zhang KHL, Sushko PV, Colby R, et al. Reversible nano-structuring of SrCrO3−δ through oxidation and reduction at low temperature. Nat Commun, 2014, 5: 4669CrossRefGoogle Scholar
  13. 13.
    Lu N, Zhang P, Zhang Q, et al. Electric-field control of tri-state phase transformation with a selective dual-ion switch. Nature, 2017, 546: 124–128CrossRefGoogle Scholar
  14. 14.
    Lu Q, Chen Y, Bluhm H, et al. Electronic structure evolution of SrCoOx during electrochemically driven phase transition probed by in situ X-ray spectroscopy. J Phys Chem C, 2016, 120: 24148–24157CrossRefGoogle Scholar
  15. 15.
    Lim J, Yu J. Role of oxygen vacancy in the spin-state change and magnetic ordering in SrCoO3−δ. Phys Rev B, 2018, 98: 085106CrossRefGoogle Scholar
  16. 16.
    Zhao J, Guo H, He X, et al. Manipulating the structural and electronic properties of epitaxial SrCoO2.5 thin films by tuning the epitaxial strain. ACS Appl Mater Interfaces, 2018, 10: 10211–10219CrossRefGoogle Scholar
  17. 17.
    Zhang Q, He X, Shi J, et al. Atomic-resolution imaging of electrically induced oxygen vacancy migration and phase transformation in SrCoO2.5−σ. Nat Commun, 2017, 8: 104CrossRefGoogle Scholar
  18. 18.
    Long Y, Kaneko Y, Ishiwata S, et al. Synthesis of cubic SrCoO3 single crystal and its anisotropic magnetic and transport properties. J Phys-Condens Matter, 2011, 23: 245601CrossRefGoogle Scholar
  19. 19.
    Lee JH, Rabe KM. Coupled magnetic-ferroelectric metal-insulator transition in epitaxially strained SrCoO3 from first principles. Phys Rev Lett, 2011, 107: 067601CrossRefGoogle Scholar
  20. 20.
    Potze RH, Sawatzky GA, Abbate M. Possibility for an intermediate-spin ground state in the charge-transfer material SrCoO3. Phys Rev B, 1995, 51: 11501–11506CrossRefGoogle Scholar
  21. 21.
    Zhuang M, Zhang W, Hu A, et al. Possible magnetic ground state in the perovskite SrCoO3. Phys Rev B, 1998, 57: 13655–13659CrossRefGoogle Scholar
  22. 22.
    Karvonen L, Valkeapaa M, Liu RS, et al. O-K and Co-L XANES study on oxygen intercalation in perovskite SrCoO3−δ. Chem Mater, 2010, 22: 70–76CrossRefGoogle Scholar

Copyright information

© Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Jiali Zhao (赵佳丽)
    • 1
    • 5
  • Yi Luo (罗毅)
    • 2
  • Jia-Ou Wang (王嘉鸥)
    • 1
  • Haijie Qian (钱海杰)
    • 1
  • Chen Liu (刘晨)
    • 1
  • Xu He (何旭)
    • 3
  • Qinghua Zhang (张庆华)
    • 4
    • 5
  • Heyi Huang (黄河意)
    • 4
    • 5
  • Bingbing Zhang (张兵兵)
    • 1
  • Shunfang Li (李顺芳)
    • 2
  • Erjia Guo (郭尔佳)
    • 4
  • Chen Ge (葛琛)
    • 4
  • Tieying Yang (杨铁莹)
    • 6
  • Xiaolong Li (李晓龙)
    • 6
  • Meng He (何萌)
    • 4
  • Lin Gu (谷林)
    • 4
    • 5
  • Kui-Juan Jin (金奎娟)
    • 4
    • 5
  • Kurash Ibrahim (奎热西•依布拉欣)
    • 1
    Email author
  • Haizhong Guo (郭海中)
    • 2
    Email author
  1. 1.Institute of High Energy PhysicsChinese Academy of SciencesBeijingChina
  2. 2.School of Physical EngineeringZhengzhou UniversityZhengzhouChina
  3. 3.Physique Théorique des Matériaux, Q-MAT CESAMUniversité de LiègeLiègeBelgium
  4. 4.Institute of PhysicsChinese Academy of SciencesBeijingChina
  5. 5.University of Chinese Academy of SciencesBeijingChina
  6. 6.Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghaiChina

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