Goal: High quality sample preparation of large areas to investigate the sample in the SEM.
Sample Size: Ø 25 mm, 12 mm thick
Process Description (benchmark values for this particular sample): Mechanical pre-preparation with Leica EM TXP: The sample was glued with super glue onto a standard SEM stub. This stub was clamped in the SEM stub adaptor of the Leica EM TXP for pre-preparation prior to ion beam milling.
For this mechanical preparation step diamond lapping foils of 9μm subsequently 2μm and finally 0.5μm grain size were used. It took about 1.5 hours. The sample was removed from the stub with a razor blade after TXP processing and fixed onto the holder of the rotary stage of the Leica EM TIC 3X.
The preparation should prove if a large area ~25mm of this sample can be ion beam polished with the EM TIC 3X rotary stage.
Ion beam (flat) milling:
| TIC 3X rotary stage | |
| Acceleration voltage | 7 kV |
| Gun current | 3 mA |
| Milling time | 40 min |
| Rotation speed | ~40 rpm |
| Lateral movement | +/- 10 mm |
Following images were taken with a table top SEM. Hence, high quality images can’t be achieved. However, following images prove an ion beam impact in the center and on 25mm rim of the oil shale sample. It shows improvements compared to the mechanical polishing step on the high mag images.
