Atomic-Resolution Holography

This chapter describes details of atomic-resolution holography, which gives a three-dimensional atomic image around a target atomic site. It can visualize the atomic structures of an impurity, a dopant, an adsorbate on a crystal, and a thin-film interface as well as the positional fluctuation of a target atom. These atomic structures cannot be measured by conventional measurement methods, such as X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), and electron microscopy. There are several types of atomic-resolution holography: X-ray fluorescence holography, neutron holography, photoelectron holography, and inverse photoelectron holography. The principle and apparatus of these techniques are introduced together with their features. Some excellent examples of hyperordered structures embedded in crystals are presented, such as the Co suboxidic structure in TiO $$_2$$ , the Eu dopant structure in CaF $$_2$$ , the P dopant structure in the diamond, the defect structure between an insulating layer and a diamond semiconductor, and so forth. Section 3.1 gives a brief introduction to atomic-resolution holography. Section 3.2 describes its principle in detail, especially, the recording processes of holograms and the reconstruction algorithms. Individual holographic techniques are introduced in Sects. 3.4, 3.5, 3.6, and 3.7. Finally, the features of these techniques are summarized in Sect. 3.8.