What is Materials Science, and how does ion scattering fit in?
‘Materials Science’ refers broadly to the study of the properties of matter, usually solids and liquids. Scientists from many areas: chemistry, engineering, medicine, dentistry, mathematics, biology, physics and others do work that can be considered materials science. Although many scientists work toward understanding nature for its own sake, much of materials science is driven by technology. For example, suppose there is a need to develop an improved joint implant to replace an arthritic hip or knee. A group of engineers build prototype materials; chemists and physicists analyze their properties. Medical doctors and biologists do experiments to determine how well the materials work inside a person’s body as a replacement joint. The scientists repeat the study over many years until they understand how to make an improved implant.
Materials science covers a vast array of fields. The auto industry wants to make better catalytic converters; chemists work to develop surfaces that convert toxic exhaust more efficiently. Metallurgists probe the weaknesses of alloys so that aircraft companies can make strong fuselages. Navies want to minimize corrosion to their ships, so surface scientists study metal degradation. Physicists measure light pulsing through crystals for laser diodes. In order to transport information more reliably, engineers analyze fiber-optic plastics.
As described above, materials science is applied to technology, however, it relies on knowledge gained through basic science. Many of its techniques have already been used in studying chemistry, physics, and biology. Ion scattering is such a borrowed technique; it is used in many sub-fields of physics, and it has a long, rich history of revealing information about the natural world. We use ion scattering to study matter by shooting a beam of charged particles with a known momentum at a target; we record how the ions are deflected by the target, and can then deduce many things about what the target contains. To begin to understand how this works, it is good to consider the Rutherford experiment, which was one of the most successful early applications of ion scattering.