Study of materials with scanning(SEM), transmission(TEM) electron microscopes, Auger electron spectroscope (AES) and Raman spectroscopy.

Many materials, like for example metals, are typically composed of a collection of very small crystallites. The nature and size of these crystallites, as well as the way in which they are arranged and the defects inside them, have a determining effect on the mechanical, electrical and many other physical properties of the material.

In this project a few of the methods, which can be used to prepare materials so that the crystal structure and defects can be observed, will be applied. Electropolishing techniques will be used to prepare metal samples so that by using optical and scanning electron microscopes (SEM) we can observe the crystals. The effect of heat treatment on the microstructure and mechanical properties (hardness) will be investigated. This will be measured by using a microhardness tester. Vacuum deposition techniques will also be applied to prepare very thin films of a metal. A transmission electron microscope (TEM) will be used at magnifications of 100000X and more to examine the crystallites and defects in the crystals. The sticking of impurities to the surface will be investigated by Auger electron spectroscopy and by the optical technique, Raman spectroscopy, which employs a high intensity laser.

Participants

• Dr. Nic van der Berg