The physical properties of diamond are some of the most interesting of natural materials. Electron energy-loss spectroscopy studies of a single crystal diamond wedge allow some of the basic electron matter interactions to be studied. The electron energy-loss spectrum has been examined with particular reference to the plasmon excitations in the crystal. The mean-free path of the electrons through the diamond crystal and the nature of the observed features in the energy-loss spectrum have been examined.

A single crystal of diamond was cut and polished to produce a diamond wedge with a 33° angle making it suitable for observation in a transmission electron microscope (Fig. 1). The determination of the geometrical parameters of the crystal wedge involved the analysis of pendellosung fringes (Fig. 2) and comparisons to bloch wave calculations. The gradient analysis plot shown in Fig. 3 allowed the wedge thickness to be determined at any distance from the edge.