Transport properties of nanoscopic solids as probed by spectroscopic techniques

Abstract Nanoscaled and ultramicroscopic solids stand for systems where the geometry and size have an important influence on their transport properties. They are hard to probe directly due to the necessity to fabricate electric circuits at minuscule dimensions. Nanoparticles with electrically conductive properties, at scales being comparable to the light wavelength and/or penetration depth of electromagnetic radiation used in spectroscopy, fall into a family of nanoscopic solids that can be investigated noninvasively, such as exceptionally applicable multiferroic BiFeO3 nanoparticles, doped nanocrystalline CeO2 utilized for fuel cell implementations, and single walled carbon nanotubes with outstanding conductive properties in molecular electronics and spintronics. In this account, we are reviewing some of the indirectly inferred transport properties of these novel multifunctional materials in the light of contactless spectroscopic method which involves the following three experimental techniques: Raman scattering, infrared reflection, and electron spin resonance. A particular attention has been paid to the theoretical background outlined in this chapter to understand the link between the highly informative spectroscopic data and electric conductivity.