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Elucidation of local structure deformation in κ−(BEDT−TTF)2Cu[N(CN)2]Br by x-ray fluorescence holography
- Source :
- Physical Review B. 103
- Publication Year :
- 2021
- Publisher :
- American Physical Society (APS), 2021.
-
Abstract
- $\ensuremath{\kappa}\text{\ensuremath{-}}{(\mathrm{BEDT}\text{\ensuremath{-}}\mathrm{TTF})}_{2}\mathrm{Cu}[\mathrm{N}{(\mathrm{CN})}_{2}]\mathrm{Br} (\ensuremath{\kappa}\text{\ensuremath{-}}\mathrm{Br})$ is an organic superconductor that changes to an Anderson-type insulator due to the random defects introduced by x-ray irradiation. In this study, we directly investigated the effects of irradiation on the local structures in the anion layer of $\ensuremath{\kappa}\text{\ensuremath{-}}\mathrm{Br}$ using x-ray fluorescence holography. The local structures around the Cu atoms in the anion layer were directly reconstructed from holograms. Prior to radiation damage, the reconstruction clearly shows the atomic images of the Br and N atoms that are directly coordinated to Cu. In the irradiated samples, the N images in the reconstructions were strongly suppressed as a result of the positional fluctuations of N introduced by the defects induced by irradiation. Using the previously proposed ``bond-shifted'' model and the thermal vibration amplitudes calculated from molecular dynamics simulations, we simulated the holograms and the atomic reconstructions of the anion layer. The simulations show that the ``bond-shifted'' model, along with thermal vibrations at 100 K, suppresses the N atomic images, as was observed in the experimental reconstructions.
- Subjects :
- Materials science
02 engineering and technology
021001 nanoscience & nanotechnology
01 natural sciences
Local structure
Fluorescence
Ion
Crystallography
Molecular dynamics
0103 physical sciences
Organic superconductor
Irradiation
Deformation (engineering)
010306 general physics
0210 nano-technology
X-ray fluorescence holography
Subjects
Details
- ISSN :
- 24699969 and 24699950
- Volume :
- 103
- Database :
- OpenAIRE
- Journal :
- Physical Review B
- Accession number :
- edsair.doi...........5a13568a89fb8287aa79141d461d1c38