Investigation of thermostability and phonon-phonon interactions in Mo_6S_3I_6 nanowires by Raman scattering spectroscopy

摘要

Detailed Raman scattering measurements were performed on molybdenum-sulfur-iodine nanowires (Mo_6S_3I_6). At room temperature, 21 well-resolved Ramanmodes were experimentally observed for the first time in this new compound. The phase stability and vibrational properties of the nanowireswere investigated by different temperature treatments. High-temperature Raman spectra showed that the phase separation of Mo_6S_3I_6 nanowires took place between 573 and 673 K, followed by appearance of a new mode at 819 cm~(-1) characteristic of the MoO_3 phase. Low-temperature Raman scattering spectra showed a significant difference in phonon-phonon interactions between internal and external Raman modes of Mo_6S_3I_6 nanowires. These interesting vibrational properties can give new insights for improved material preparation and achievement of higher conductivity and other functional properties of these otherwise interesting materials.