<研究ノート>有機導電体における振動分光学的研究

Abstract

The molecular vibration can be probed through infrared and Raman spectroscopies, which are called "vibration spectroscopy". The vibrational spectroscopy shows the advantageous feature on the analysis of the charge disproportionation in organic solids. In this article, the analysis of the electronic structure of an organic conductor, (MeEDO-TTF)[2]PF[6], is reviewed. The black plate modification of (MeEDO-TTF)[2]PF[6] exhibited the semiconductor-to-semiconductor phase transition at around room temperature. The donor molecules in both of the high- and low-temperature phases showed similar packing patterns, based on which the tight-binding approximation afforded the similar band structures and Fermi surfaces. The vibrational spectra proved that the nearly localized charge disproportionation takes place in the high-temperature phase and the distinct charge disproportionation is developed in the low-temperature phase.