ELECTRONIC-STRUCTURE OF AMORPHOUS SI MEASURED BY (E,2E)-SPECTROSCOPY

Energy-resolved electron momentum densities are determined for a thin Si film evaporated onto a carbon foil. This is done by transmission (e ,2e) spectroscopy, a technique that does not rely on crystal momentum and is therefore ideally suited for the study of amorphous materials. Spectra were collected with an energy resolution of 2 eV and a momentu m resolution of 0.15 an (0.3 Angstrom(-1)). The main feature disperses in a strikingly similar way to the crystalline ones. In addition to t he dispersion the intensities of the peaks are obtained. In spite of h aving only a qualitative understanding of the shape of the spectra, th e results of the comparison of measured amorphous momentum densities w ith calculated crystalline ones are reasonable. The basis of this agre ement between amorphous solid and crystalline theory is discussed.