The need for high-performance materials in industrial settings, in the home, and in military applications has led to an explosion of research directed towards the creation of new materials. Scientists are being asked to develop materials that can withstand hostile environments such as high temperature, mechanical stress, or the presence of corrosive agents. Other efforts have been focused on creating catalysts to direct reactions selectively and give products in high yield. In some cases, substances must display high strength and modulus, yet retain a light weight. Still other applications require unique optical or electrical properties, such as high conductivity, insulating capacity, or large nonlinearity in the optical response. These properties depend upon the microstructure of the material. Of particular importance are chemical composition, preferential orientation of molecules, size of domains, sample heterogeneity, and motional properties of the substance or molecules contained within.
Tom M. Apple, "NMR Applied to Materials Analysis," Appl. Spectrosc. 49, 12A-20A (1995)