Abstract
In order to observe high-spatial-resolution elemental images using inelastic electrons, a 300 kV energy-filtering transmission electron microscope with an omega-type energy filter has been developed. Some characteristic features of the new microscope are described. The accelerating voltage dependence of the inelastic images is calculated to confirm that the spatial resolution for the elemental images is improved with an increase in the voltage from 120 kV to 300 kV. It is shown that a single atomic layer of oxygen atoms in Al 11 O 3 N 9 crystal is well imaged as a bright line with a periodic separation of 2.9 nm along the c-axis. The spatial resolution for the oxygen images is about 0.5 nm, which corresponds well with the theoretical calculation.