6. Synthesis of Materials Under High Pressure

Preparative chemistry under high pressure becomes an interesting and challenging process for the preparation of novel functional materials where the common crystallographic and thermodynamics constraints can be easily deviated. Thus, the reaction of materials under high pressure and temperature can lead to newer products which otherwise cannot be obtained by the conventional high temperature reactions. Also, such procedures can stabilize the unusual coordination number, valence states, densely packed metastable compounds. In this chapter, a brief introduction to the chemical reactions under high pressure and high temperature, and effect of pressure and pressure/temperature on the chemical equilibrium are presented. Subsequently, the evolution of high pressure synthesis experimental setups and different types of common setups used in laboratory are discussed. Finally, some of the examples of materials synthesized under high pressure conditions are presented.