Surface and bulk investigations of fullerene-based materials under high pressure and temperature by means of vibrational spectroscopy

Abstract

Metastable C 60 materials have been formed under high pressure and temperature. These carbon structures have been developed and studied in a wide spectral range by Fourier transform infrared spectroscopy (FTIR) and micro-Raman spectroscopy. The FTIR spectra of carbon-based polymer materials (pristine fullerenes, carbon nanostructures, diamond-like C 60 forms) were recorded in the 4000-10 cm -1 region. Our focus lies on low-frequency infrared (IR) spectra of fullerene and metastable forms of C 60 obtained under high pressures and temperatures as well as the spectra of natural diamond and graphite in the 8-170 cm -1 region. Several new bands of diamond-like phases arise in the high pressure-temperature phase of reflection IR spectra. The band structures connected with diamond-like structures in sp 3 hydridization of the bonds observed were identified as phases of high pressure and temperature. It is our understanding that these low-frequency modes can be assigned to zone- and space-folded phonons. In addition, our observation on micro-Raman spectra of these carbon-based materials and their new forms allowed us to determine the level of disorder in these types of polymer forms of carbon, as well as to study the formation of unusual nanostructures.