7: Synthesis and Fabrication

As mentioned in Section 1.1, solids can be classified based on various criteria such as their elemental composition, the nature of the interactions present, and their types of applications. Materials in general can also be grouped into various classes such as solids, colloids, ultrathin films, etc., based on their physical state and assembly. A wide range of techniques are used to prepare different classes of materials and even specific members of these classes. This chapter presents several key concepts that guide the synthesis and fabrication of materials; it may be noted however, that the list presented here is by no means exhaustive, in view of the emergence and continuing evolution of several specialized techniques for materials synthesis. The term ‘synthesis’ is generally used to describe the formation of new chemical entities, often through the formation of covalent bonds; it could also be used to denote the formation of ionic materials. ‘Fabrication’ is a more general term used to describe assemblies of molecular units, organization of layers or subunits of materials, construction of device structures etc. Together, these terms can be used to discuss the formation of materials with different compositions, structures, and functions.