Morphology and crystallography of nanoparticulates revealed by electron holography

Abstract

Electron holography permits the precise determination of aspects of the morphology of nanometer-sized particulates, because the pure phase information ill the image wave call be reconstructed and displayed. Profiles of intensity over the phase image are, in particularly advantageous cases, directly related to particle morphology, since the phase intensity for materials that are essentially kinematic scatterers and are of homogeneous composition is directly related to thickness. Holograms at high resolution can also be used for many other analyses of a material's structure; they provide,for example, a method for precise calibration of lattice spacings in nanometer-sized areas, that allows for the correlation of structure to processing parameters. Examples of the use of holography for studies of nanoparticles of oxides and model catalysts are given.