Supercooled Liquids and Glasses by Dielectric Relaxation Spectroscopy

The formation of a glassy disordered solid is usually observed upon cooling a melt when crystallization can be avoided or when a system is incapable of crystallizing, as is the case with some polymers. Such glass-forming materials are considered supercooled within the temperature range between glass transition temperature (Tg) and Tm. This chapter first reviews the basics of the electrostatics required to assess the advantages and limitations of the broadband dielectric spectroscopy. It then compiles the properties of common response functions used. The chapter discusses the selection of linear experimental techniques and nonlinear techniques. Finally, the chapter compiles a variety of examples of dielectric experiments that are capable of providing key insight into understanding viscous liquids and other soft matter. The coverage of dielectric relaxation based approaches to supercooled liquids and glasses showcases the versatility and power of dielectric techniques in this field.