Raman Study on Carbonaceous Materials Prepared by Mechanical Milling

Through Raman spectroscopy studies, we show that mechanical grinding generates an increasing amount of unorganized carbon at a rate depending on the type of grinding mode used (Shear and Shock-type grinding). The first-order Raman spectrum for pure unground graphite has a well-known G sharp band at 1579 cm(-1), which corresponds to the E(2g) vibration while the ground samples present a broadened G band accompanied by new components at about 1610 cm(-1) (D'), 1510 cm(-1) (D ") and 1348 cm(-1) (D), usually explained as arising from disorder and defects'. Shock-type grinding produces a faster disorder increase than shear-type grinding. The latter preserves part of the graphitic character. The general effect of mechanical milling remains however opposite to that of Thermal Treatment (Graphitization).