Boson Peak And Fracton Of Polymethyl Methacrylate Detected By Terahertz Time-Domain And Low-Frequency Raman Spectroscopies

Terahertz time-domain spectroscopy and lowfrequency Raman scattering were performed on polymethyl
methacrylate to detect boson peak (BPs) and fractons, which are universal excitations of glass-forming materials. In the infrared spectrum, a BP is observed in the () vs. plot, where () is the absorption coefficient. The log-log plot of (), “() and the vibrational density of states exhibit a linear frequency dependence above the BP frequency, where “() is the imaginary part of the Raman susceptibility. We determined both the infrared light vibration and Raman coupling constants to investigate the appearance of the fractal and fracton dimensions.

Presenters and Authors Info

Presenter: Anonymous

Authors: Nakagawa, Shin; Mori, Tatsuya; Fujii, Yasuhiro; Kitani, Suguru; Koreeda, Akitoshi; Kawaji, Hitoshi; Ko, Jae-Hyeon; Kojima, Seiji

Department of Physical Sciences, Ritsumeikan University, Department of Physics, Hallym University, Division of Materials Science, University of Tsukuba, Laboratory for Materials and Structures, Tokyo Institute of Technology