SPring-8 Users Community (SPRUC)

Research Group:

Atomic Resolution Holography Research Group



  Naohisa Happo
  Hiroshima City University, 3-4-1, Ozuka-Higashi,Asa-Minami-Ku,Hiroshima 731-3194 JAPAN
  Telephone: +81-(0)82-830-1553

Research Area:

Biomolecules, Fundamental Characterization, Applied Materials, Measurements



Overview of Research Group, Goals and Purposes:

Atomic Resolution Holography Research Group is based on advanced structural analysis techniques of X-ray fluorescence (XFH) and photoelectron holography (PEH), which can visualize three dimensional atomic configurations around a specific element without any special structural models. In particular, these techniques provide clear information on the structural properties of dopants, e.g., the determinations of dopant sites. This information cannot be obtained by diffraction, which can be applied only to periodic lattices. XFH and PEH have successfully clarified dopant sites and lattice distortions in various materials, such as semiconductors, superconductors, magnetic materials, applied materials and protain crystals including metal, which lead us to the atomic-level insight into the origin of the physical properties of materials. Furthermore, these techniques are very sensitive to distortions of surrounding atoms, and thus, they can be applied also to the evaluation of lattice distortions in mixed crystal systems.

The purpose of this research group is to arrange the platform so that researchers can freely access to this new structural information. In the first to the forth periods, We established measurement techniques of XFH and PEH at SPring-8 and developed valence selective measurements, measurements with external fields and at low temperatures using a cryogenic system. The number of researchers using these techniques has increased drastically, and the arrangement of the platform is well designed. In this period, we will apply them to a wide variety of materials, and develop further for this tequnique. In the research group meetings, we will discuss and summarize the requirements from each members, and reflect them for the development of experimental techniques.