Energy-Filtered Imaging: A Tutorial

Abstract

Over the several years that imaging energy filters have been available commercially, numerous and wide-ranging applications have demonstrated elemental mapping with a resolution approaching 1 nm. A few reports have even shown resolutions <0.4 nm. Elemental mapping by energy-filtered transmission electron microscopy (EFTEM) is clearly an attractive and powerful tool, but some aspects of the techniques can be complex, with many pitfalls awaiting the unwary. This tutorial aims to cover some practical aspects of elemental mapping by EFTEM. It is based largely on the author's work at the ORNL SHaRE User Facility, where EFTEM research has been performed since 1994 with a Gatan imaging filter (GIF) interfaced to a Philips CM30T operated at 300 kV with a LaBa cathode.120 Most of the applications have been to metals and ceramics, emphasizing interfacial segregation and precipitation.For quantitative composition mapping by EFTEM a number of interrelated parameters [field of view, resolution (δ),