Giant photoinduced lattice distortion in oxygen vacancy ordered thin films
- Chinese Academy of Sciences (CAS), Beijing (China). Inst. of High Energy Physics
- Univ. de Liège (Belgium)
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Physics
- Zhengzhou Univ. (China)
Despite the progress in understanding the formation and migration of oxygen vacancies in strongly correlated complex oxides, few studies focused on the dynamic behaviors of the oxygen vacancies under the transient and non-equilibrium states. Here we report a series of multi-timescale ultrafast X-ray diffraction experiments using picosecond synchrotron and femtosecond table-top X-ray sources to monitor the structural dynamics in oxygen-vacancy-ordered SrCoO2.5 thin films excited by photons. A giant photoinduced structure distortion in c-axis direction (with strain $Δc/c$ > 1%) was observed, higher than any previously reported data in the other transition metal oxide films. The femtosecond X-ray diffraction reveals the formation and propagation of the coherent acoustic phonons, indicating an instantaneous and a much larger photoinduced stress within the first 100 ps. Density Function Theory reproduced the photostrictive responses and the strong dependence on excitation wavelength as observed in the experiment. The combined experimental and theoretic results demonstrate that the photoexcitation of bonding to antibonding state via charge transfer is the dominant mechanism in the SrCoO2.5 thin films distinct from the depolarization effect by photoinduced carriers in the other perovskite oxides.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Organization:
- National Natural Science Foundation of China (NSFC); USDOE Office of Science (SC), Basic Energy Sciences (BES); Australian Research Council (ARC); Fund for Scientific Research (F.R.S.–FNRS); theWalloon Region
- Grant/Contract Number:
- AC02-06CH11357; 11574365; 11905242; 2.5020.1; 1117545
- OSTI ID:
- 1576749
- Journal Information:
- Physical Review B, Vol. 100, Issue 14; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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