The recent use is reported of neutron activation analysis to determine the elemental content of silicon-germanium layers that were epitaxially grown on antimony-doped single crystal silicon substrates. The substrates formed part of gold-contact Schottky diode circuits. Gamma rays from the activation products 75Ge and 77Ge were used, and the usefulness was demonstrated of the gallium Kα X ray, emitted in the electron capture decay of 71 Ge, to identify and quantify the germanium in our samples. Minor components of the silicon matrix and their bulk atomic concentrations for specimens having masses of ∼56 mg were germanium (4 ppm), gold (2 ppm), and antimony (32 ppm). Estimates for the germanium atom fraction x, in the layers, in the range of 6 to 8%, were obtained for the samples studied.