Back to Search
Start Over
Coupling of molecular motion and electronic state in the organic molecular dimer Mott insulator β′ -(BEDT-TTF) 2ICl2
- Source :
- Physical Review B. 97
- Publication Year :
- 2018
- Publisher :
- American Physical Society (APS), 2018.
-
Abstract
- We have performed $^{1}\mathrm{H}$ NMR and $^{13}\mathrm{C}$ NMR measurements to investigate the coupling between molecular dynamics and the electronic state of ${\ensuremath{\beta}}^{\ensuremath{'}}$-(BEDT-TTF)${}_{2}{\mathrm{ICl}}_{2}$. From the $^{1}\mathrm{H}$ NMR measurements, we observed a frequency-dependent anomaly in the nuclear spin-lattice relaxation rate $^{1}\mathrm{T}_{1}^{\ensuremath{-}1}$ that originates from the slowing down of the ethylene motion. In the $^{13}\mathrm{C}$ NMR measurements, we found an anomaly in the linewidth of the NMR spectra at around 150 K, which is attributed to a nuclear spin-spin relaxation rate $(^{13}\mathrm{T}_{2})$ anomaly. The magnitudes of the anomalies in the linewidth and in $^{13}\mathrm{T}_{2}^{\ensuremath{-}1}$ are related to the hyperfine coupling constant. These results suggest that the ethylene motion modulates the molecular orbital of the BEDT-TTF molecules and gives rise to a difference in the orbital energy between the ``staggered'' and ``eclipsed'' conformations. We propose that significant coupling exists between the ethylene motion and the electronic state of the molecular dimer and that the ethylene dynamics can trigger the emergence of charge degrees of freedom inside the dimers and cause the dielectric anomaly in ${\ensuremath{\beta}}^{\ensuremath{'}}$-(BEDT-TTF)${}_{2}{\mathrm{ICl}}_{2}$.
- Subjects :
- Physics
Mott insulator
Dimer
Charge (physics)
02 engineering and technology
021001 nanoscience & nanotechnology
Coupling (probability)
01 natural sciences
NMR spectra database
Specific orbital energy
Crystallography
chemistry.chemical_compound
chemistry
0103 physical sciences
Condensed Matter::Strongly Correlated Electrons
Molecular orbital
Anomaly (physics)
010306 general physics
0210 nano-technology
Subjects
Details
- ISSN :
- 24699969 and 24699950
- Volume :
- 97
- Database :
- OpenAIRE
- Journal :
- Physical Review B
- Accession number :
- edsair.doi...........60dce6ded9c1bc943f074691153835a3
- Full Text :
- https://doi.org/10.1103/physrevb.97.045136