Possible Lubrication Mechanism of Carbon Onions

Another explanation can be formulated by using recent results obtained by Oleshko and Howe. They postulated that it is possible to determine the physical properties of materials from the low-loss peak obtained by EELS measurements [33,62]. For isotropic or amorphous 

Density can also be determined from EELS measurements. Xu et al. used electron energy-loss spectroscopy (EELS) to characterize hydrogen-free tetrahedral amorphous carbon films [65]. They studied several carbon film materials deposited with different bias voltages. From their results, it is possible to fit a good correlation between the density (Z ) of the carbon films tested and the maximum of the low loss plasmon peak ( p). Thus, Xu obtained an empirical relation as follows  

Using this relation, the densities of the graphite and carbon onions were tentatively determined at 2897 and 2593 kg/m, respectively. These values are higher than data from the 

---