SEM Observation at High Magnification and EDX Analysis of Insulating Sample by Diluted Ionic Liquid

Abstract

A few micro liters of 10 −2 wt.% ionic liquid diluted by ethanol or acetone dropped onto insulating samples made it possible to observe scanning electron microscope (SEM) image at 5000 magnification, which is as clear as Pt-Pd sputtering. SEM-EDX analysis of sulfur is possible when using sulfur-free ionic liquid diluted down to 10 −2 wt.%. Quantitative analysis using the ZAF method is also possible for insulating samples.

Possibility of Scanning Electron Microscope Observation and Energy Dispersive X-Ray Analysis in Microscale Region of Insulating Samples Using Diluted Ionic Liquid

“…We obtained clear SEM images at 5,000× magnification at 10 −3 Pa by dropping a few microliters of 10 −2 wt% ionic liquid diluted with ethanol or acetone onto a fossil ( Baculogypsina sp.) as shown in Figure 1 (Ze et al, 2011). In addition, we verified that it is possible to perform qualitative elemental analysis of the fossil with energy dispersive X-ray (EDX) spectroscopy using 10 −2 wt% of 1-ethyl-3-methylimidazolium acetate (EMI-CH 3 COO).…”

Effect of electrical charging on scanning electron microscopy-energy dispersive X-ray spectroscopy analysis of insulating materials

“…In the SEM-EDX analysis of a fossil (Baculogypsina sp.) using 1 wt% EMI-CH 3 COO, the following cations were detected: 75 wt% calcium, 20 wt% magnesium, and 5 wt% aluminum [5]. We can thus use diluted EMI-CH 3 COO in SEM-EDX analysis, except for the analyses of hydrogen, carbon, nitrogen, and oxygen.…”

“…In addition, it is not possible to observe or analyze insulating materials in micrometer-scale area by the same method because a thick ionic liquid layer forms on the insulating materials and prevents the electron beam from reaching the surface. We resolved these difficulties by dripping several micro-liters of 1 wt% EMI-CH 3 COO onto the insulating materials [1,5].…”