In-depth evaluation of the electron beam-induced damage on the accuracy of EDS quantification of zeolite

Electron-beam damage can compromise quantitative SEM-EDS analysis of zeolites. We examined how irradiation mode, probe current, acquisition time, total dose, and raster area affected the quantitative results and surface condition of HEU-type zeolite. Point analysis produced localized craters and surface traces, accompanied by decreases in Total and the measured Na and Al concentrations. At a total dose of 30 nC, raster scanning over 2 × 3 µm kept Total close to the expected range, whereas point analysis yielded lower Totals even when the charge-balance error remained small. Thus, Total and charge balance must be evaluated together when assessing the effects of irradiation on quantitative results. The 2 × 3 µm raster provided local compositional information, but larger raster areas of approximately 16 × 24 µm and above generally reduced observable surface changes. The choice of raster area therefore depends on whether the analysis prioritizes local compositional information or preservation of the observable surface. A heat-diffusion simulation using the incident electron-beam energy as a surface heat source predicted a lower temperature rise for raster irradiation than for point irradiation. The calculated thermal response was approximately four orders of magnitude faster than the observed progression of surface damage, indicating that thermal diffusion alone does not describe that progression.