Image: Gold Sputter Coater
Gold Sputter Coater Unit – EMITECH K550
The gold sputter coater is a machine that we use to coat the mounted specimens in gold before they go into the SEM. The reason why we gold coat the specimens is because the SEM uses an electron beam instead of a light globe to illuminate the specimen. There are two detectors in the SEM chamber that are used to detect the two types of electrons that are bouncing of the gold metal specimen. It is these electrons - secondary and backscatter that go to make up an image of the specimen. This image of the electrons is what we are seeing, not the reflected light image we see in a light microscope. If the specimen is not finely covered with a metal like gold we will get a very poor signal thus the image derived will be very dark and perhaps not even there.
- Martin Pueschel
- © Australian Museum