MORPHOLOGY AND CRYSTALLOGRAPHY OF NANOPARTICULATES REVEALED BY ELECTRON HOLOGRAPHY

Electron holography permits the precise determination of aspects of th e morphology of nanometer-sized particulates, because the pure phase i nformation ill the image wave call be reconstructed and displayed. Pro files of intensity over the phase image are, in particularly advantage ous cases, directly related to particle morphology, since the phase in tensity for materials that are essentially kinematic scatterers and ar e of homogeneous composition is directly related to thickness. Hologra ms at high resolution can also be used for many other analyses of a ma terial's structure; they provide,for example, a method for precise cal ibration of lattice spacings in nanometer-sized areas, that allows for the correlation of structure to processing parameters. Examples of th e use of holography for studies of nanoparticles of oxides and model c atalysts are given.