The sample needs to be properly cleaned and dried before being placed on the SEM stage. It is important to remove any dust or debris that could interfere with the imaging process.
A conductive coating, such as gold or carbon, should be used to prevent charging and improve image quality. The coating should be applied evenly and thinly to avoid distorting the sample's features.
The specific voltage and current settings may vary depending on the sample and instrument, but a typical range is 5-30 kV and 10-100 μA. Higher voltages can provide better resolution, but also increase the risk of damaging the sample.
Sample drift can be minimized by using a low vacuum mode, ensuring the sample is properly mounted and coated, and avoiding excessive movements or vibrations during imaging.
SEM images show the surface topography and composition of the sample at a high magnification. They can provide information on the size, shape, and distribution of particles or features on the sample surface. Advanced techniques, such as elemental mapping, can also reveal the chemical composition of the sample.