Investigation of thermostability of Mo6S3I6 nanowires using Raman spectroscopy

Abstract

The thermostability (phase stability) of Mo6S3I6 nanowires was investigated by Raman spectroscopy, varying the incident laser power (1-9 mW) or by gradual heating of the sample from room temperature to 600°C. We have noticed 18 Raman modes in the room temperature Raman spectra, which is in good agreement with the factor group analysis prediction for P1 space group. We confirmed that the vibrations of Mo6S8 clusters dominate in vibrational properties of the Mo6S3I6 nanostructure, since nanowires Raman spectra are similar to Chevrel phase Raman spectra. During the temperature treatment, it was established that in the temperature range between 300 and 400°C a new Raman mode appeares. This mode can be ascribed to molybdenum oxide (MoO3). With further temperature increase, the intensity of this mode increases, drawing a conclusion that at temperature above 300°C the phase separation takes place in this system followed by a formation of oxide layer.

Keywords

• Mo6S3I6 nanowires
• Raman spectroscopy
• thermostability