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We describe a technique for efficient, quantitative, standardless elemental mapping using a high-angle annular detector in a scanning transmission electron microscope (STEM) to collect elastically scattered electrons. With a single crystal specimen, contrast due to thickness variations, diffraction, and channelling effects can be avoided, so that the resulting image contrast quantitatively reflects variations in impurity concentration. We compare a number of simple analytical approximations to the elastic scattering cross sections and show that a standardless analysis is possible over a wide range of atomic number and inner detector angle to an absolute accuracy of better than 20%.

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Nanometer scale holes and lines have been produced directly in calcium fluoride, aluminium oxide, and magnesium oxide by an intense beam of electrons. There is a threshold beam current density for drilling, and the variation of this with voltage has been studied. Observations using electron energy loss spectroscopy have confirmed that metallic aluminium is produced during the drilling of aluminium oxide. Aluminium oxide may be drilled when in contact with the aluminium substrate, which remains undrilled.