IN SITU COMPOSITION ANALYSIS BY EDS AT ELEVATED TEMPERATURES IN SEM AND STEM

摘要

We discuss possibilities and challenges of energy-dispersive X-ray spectroscopy (EDS) and EDS element mapping at elevated temperatures in SEM and STEM. An electron transparent Pd-Au-nanoparticle test structure on carbon film is one example. The agglomeration and evaporation of nanoparticle material during heating from room temperature up to 1,000 °C [1] in a conventional STEM were studied. Chemical phase analysis and simple statistical methods were applied to quantify the areal coverage of different species and its change with rising temperature. Heat radiation at elevated temperatures changes the low energy part of EDS spectra. We demonstrate, that element identification below 2 kV and chemical phase analysis are still possible within certain limits. For example, nitrogen can be detected up to 900 °C (Fig. 1). The results of phase and particle analysis (Fig. 2) demonstrate the capabilities of in-situ EDS in combination with statistical methods. Material agglomeration and evaporation of one involved species during heating could be quantified by areal coverage. The stability of the heating holder during temperature change ensured very low drift and successful element mapping and tracking [1].