Selection of suitable material for preparing an electron microscope sample

The most commonly used material to prepare samples of an electron microscope is gold. Gold provides high-quality microscopic images due to its high electrical conductivity and small grain size. For the EDX process, carbon layer instead of gold is used in the sample preparation process. Carbon has a small atomic number, and unlike gold, it does not add any peak to the X-ray spectrum of the specimens.

For high-resolution (high-resolution) electron microscopic processes, the use of materials such as chromium (Cr), iridium (air), tungsten (W) is recommended. Due to very fine grain size, these materials enhance the image quality and resolution. These materials have a low sputtering rate and, due to their oxidize ability, should be deposited with a turbo-molecular pumped system in a high vacuum environment. Other materials used to prepare electron microscopic samples, such as silver, platinum. Palladium has the advantage of being able to dissolve and eliminate so that the sample can be returned to the pre-deposition condition.

electron microscope