Spectrum lines across planar interfaces by energy-filtered TEM

Abstract

Electron energy-loss spectrum imaging, in which a spectrum is recorded for each pixel as a focused probe is digitally rastered in a two-dimensional pattern on the specimen, has developed into a practical and powerful microanalytical technique. However, even for only a modest number of pixels, acquisition times can become inconveniently long. One-dimensional data (spectrum lines) are often sufficient for many materials science applications, especially for planar interfaces. As well as producing energy-filtered TEM images (or diffraction patterns), the Gatan imaging filter (GIF™) can be used to acquire spectrum lines in the TEM mode, without the need to form a small probe. The basis for this capability is that for the GIF spectroscopy mode a line focus normal to the energy dispersion direction is employed. Spectra as a function of position (TEM operating in the image mode) or scattering angle (TEM operating in diffraction mode) are thus produced.