ABSTRACT
A characteristic of many solids is their crystalline state, i.e., a crystal is a solid bounded by faces meeting in definite angles. Except in the so-called regular system of crystals (cube, octahedron, etc.), the properties of a crystalline solid, such as elasticity, thermal conductivity, refractive index, etc., are different in different directions. In many systems, for example, photography, the microcrystals of silver are of much importance. The application of STM and AFM to the studies of crystal structures has been of much interest. This arises from the fact that the images obtained are three-dimensional as compared to any other microscopic analysis. Because the amount of sample needed is very small, less than
m
g, it enables studies of a much wider range of substances. Further, even though it may not be obvious, crystal formation is also determined by interfacial forces.
