Quantitative Energy-Filtering Transmission Electron Microscopy (EFTEM)

Abstract

Energy-filtered transmission electron microscopy (EFTEM) can be used to acquire elemental distribution images at high lateral resolution within short acquisition times. In this paper we discuss the unique advantages of EFTEM in terms of information content, resolution, sensitivity and detection limits. Applications in different fields of research, both in materials science and in life sciences, demonstrate the potential of EFTEM for characterizing nano-sized structures. In the first example, we show how secondary phases in a steel specimen can be easily detected by recording jump ratio images of the matrix element under rocking beam illumination. Secondly, we describe how elemental maps can be converted into concentration maps by calculating atomic ratio maps. Thirdly, we show how the energy-loss near edge structures (ELNES) can be used for mapping chemical bonding states thus differentiating between various modifications of an element. Finally, we present recent results on investigations of deposits in lung tissues and how useful EFTEM can be for defect analysis in semiconductor devices.