Extended Fine Structure on the Carbon Core-Ionization Edge Obtained from Nanometer-Sized Areas with Electron-Energy-Loss Spectroscopy

Extended fine structure, equivalent to extended x-ray-absorption fine structure, has been observed on carbon $K$-ionization edges obtained with electron energy-loss spectroscopy utilizing 0.75- to 5-nm radius probe sizes, and sampling as few as ${10}^4$ atoms in times as short as 4 min. Radial distribution functions show the expected behavior for graphite and an amorphous carbon sample. A second "amorphous" sample, however, shows structure which suggests the existence of local tetrahedral coordination.