Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
CHARACTERIZATION METHODS. 59 4 Characterization Methods. Nanometer-scale materials have certain distinguishing features that must be characterized in order to understand the relationships between their unique composition and structures and their properties. Since many materials properties, like magnetic, optical, and electrical properties, depend strongly on the atomic arrangements in the material (e.g., nearest-neighbor distances, coordination numbers), whereas others such as mechanical properties can depend also on morphological structure, knowledge of the structure of nanophase materials is important on both atomic and nanometer scales. Among the features that need to be elucidated are (1) grain and pore size distributions, morphologies, particle size, and surface area; (2) the nature and morphologies of their grain boundaries and interphase interfaces; (3) composition profiles across grains and interfaces; (4) perfection and the nature of intragrain defects; and (5) identification of residual trapped species from processing (e.g., gas or surfactant entrapment). Because of the ultrafine-scale of these nanophase materials, characterization can be a challenge in itself, and some traditional characterization tools are no longer easily applied. For the characterization of the structure and morphologies of nanoscale materials, traditional tools such as electron microscopy and x-ray and neutron scattering are both necessary and useful. However, for microchemical analysis of the materials on the requisite fine scale, further advancements in the state of the art of instrumental capabilities will be necessary in order to obtain the desired lateral spatial resolution. Useful more conventional techniques include Rutherford Back Scattering (RBS), Electron Energy Loss Spectroscopy (EXAFS), X-Ray Photo-electron Spectroscopy (XPS), Nuclear Magnetic Resonance (NMR), Raman and infrared spectroscopy, Mössbauer, and traditional adsorption techniques.
