*5.1.3 Volatile and Non-Conductive*

If the sample does not contain moisture but is also a non-conductive material, that is, if it is not possible to take an image without coating, the following should be applied. Even if many materials are dry and insulating, they can cause gas to come out in high vacuum. For this reason, it is sufficient to cover the samples containing non-volatile elements and non-conductive properties with a thin layer such as Au, C, Au/Pd and Al. This layer is generally 20–30 nm thick [4, 6]. There are some reasons why we do this.


Coatings are usually made by evaporation. If the coating is made with carbon, gold plating will be preferred since it cannot accurately analyze the amount of carbon in the sample in X-ray microanalysis. In addition, it should not be preferred too much as it will oxidize in aluminum [6].

Coated and uncoated sample images are given in **Figure 11** [8]. Since the coated sample increases the surface conductivity here, electrons from the electron gun do not cause accumulation on the surface. This provides a much more detailed and clear image of a coated sample.
