@article{6a2681fd8aaf4632bcba3317db330d83,
title = "Charge ordering and low-temperature lattice distortion in the β′ -(BEDT- TTF)2CF3CF2SO3 dimer Mott insulator",
abstract = "We present single-crystal x-ray diffraction measurements, optical investigations, and electronic structure calculations for the organic charge-transfer salt β′-(BEDT-TTF)2CF3CF2SO3 synthesized by electrocrystallization. Electronic structure calculations confirm the quasi-one-dimensional behavior of the compound and optical conductivity measurements reveal the dimer-Mott insulating nature of the system. The splitting of the charge-sensitive ν2 mode in Raman spectra demonstrates the onset of an interlayer charge-ordered phase below 25 K, also suggested by the crystal structure considerations. This transition is accompanied by clear signatures of a lattice distortion in the BEDT-TTF donor layer, as shown by a splitting of the vibrational ν3 mode in infrared spectra. At the same time, the sharp redshift of the ν1 mode involving the BEDT-TTF ethylene groups strongly suggests a significant modification of the hydrogen-type bonding present between the BEDT-TTF donor layer and the CF3CF2SO3- anion layer. These observations point to a subtle interplay of charge and lattice degrees of freedom at the phase transition.",
author = "I. Olejniczak and R. Weso{\l}owski and Jeschke, {H. O.} and R. Valent{\'i} and B. Barszcz and Schlueter, {J. A.}",
note = "Funding Information: J.A.S. acknowledges support from the Independent Research/Development program while serving at the National Science Foundation. This work was supported by UChicago Argonne, LLC, operator of Argonne National Laboratory ({"}Argonne{"}). Argonne, a US Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. H.O.J. and R.V. acknowledge funding from the Deutsche Forschungsgemeinschaft within collaborative research center SFB/TR 49. The authors thank Janice L. Musfeldt for help in room-temperature FIR and NIR reflectance measurements, and numerous discussions. We also thank R. Wojciechowski for help in the interpretation of Raman spectra. We thank Brian H. Ward for his contributions to the synthetic effort at Argonne. Funding Information: J.A.S. acknowledges support from the Independent Research/Development program while serving at the National Science Foundation. This work was supported by UChicago Argonne, LLC, operator of Argonne National Laboratory (“Argonne”). Argonne, a US Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. H.O.J. and R.V. acknowledge funding from the Deutsche Forschungsgemeinschaft within collaborative research center SFB/TR 49. The authors thank Janice L. Musfeldt for help in room-temperature FIR and NIR reflectance measurements, and numerous discussions. We also thank R. Wojciechowski for help in the interpretation of Raman spectra. We thank Brian H. Ward for his contributions to the synthetic effort at Argonne. Publisher Copyright: {\textcopyright} 2020 American Physical Society.",
year = "2020",
month = jan,
day = "29",
doi = "10.1103/PhysRevB.101.035150",
language = "English",
volume = "101",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "3",
}