Studying thermal effects of laser excitation power on carbonaceous meteorites by Raman spectroscopy

Carbonaceous chondritic meteorites can provide valuable clues about planet formation since they are considered some of the most primitive surviving materials of our solar system. This information can be obtained through their physical properties which can be characterized using microscopy and spectroscopy techniques. In particular, Raman spectroscopy has been used extensively on meteoritic samples since it is a nondestructive tool that provides information about their structure and mineralogical composition. However, the power of the laser excitation source used in this technique can alter the properties of the samples due to thermal effects. Hence, it is critical to analyze in detail what alterations could be produced in a meteoritic sample due to the laser power to obtain reliable information about its physical properties, and thus, provide the right evidence to understand the origin of these relics. In this work, we study in detail the laser-induced thermal effects produced on carbonaceous chondritic meteorites by analyzing the Raman spectra parameters of the minerals found in these samples as a function of the laser excitation power and correlating them with changes that can occur on the topography of the irradiated regions using optical microscopy.