TY  - JOUR
AU  - Zschornak, Matthias
AU  - Richter, Carsten
AU  - Nentwich, Melanie
AU  - Stöcker, Hartmut
AU  - Gemming, Sibylle
AU  - Meyer, Dirk C.
TI  - Probing a crystal's short-range structure and local orbitals by Resonant X-ray Diffraction methods
JO  - Crystal research and technology
VL  - 49
IS  - 1
SN  - 0232-1300
CY  - Weinheim
PB  - Wiley-VCH
M1  - DESY-2014-01881
SP  - 43 - 54
PY  - 2014
AB  - Diffraction Anomalous Fine Structure (DAFS) combines the long-range, crystallographic sensitivity of X-ray diffraction with the short-range sensitivity of X-ray Absorption Spectroscopy (XAS). In comparison to other spectroscopic methods, DAFS can additionally distinguish phases of different translational symmetry by choice of momentum transfer, or isolate spectra from chemically identical atoms on various Wyckoff sites of a crystal's structure using crystallographic weights. The Anisotropy of Anomalous Scattering (AAS) extends the concept of isotropically scattering atoms to a more general case, where the atom's scattering characteristics depend on the polarization as well as the wavevector of the incident and scattered X-rays. These can be written as tensors that reflect the local site symmetries of the resonant atom. Forbidden Reflection Near-Edge Diffraction (FRED) is an elegant way to measure AAS by using reflections that are extinguished in the special case of isotropically scattering atoms. They can only be observed due to the non-isotropic contributions at photon energies in the vicinity of an absorption edge where electronic transitions occur. Combining the site selectivity of DAFS with the information accessible through AAS allows probing the short-range order and local orbitals of selected atoms in a crystal structure of a chosen phase. The present condensed review gives a brief overview on the pioneer work, the theory and sensitivities as well as selected recent applications of these powerful and promising Resonant X-ray Diffraction (RXD) methods. Additionally, some recent work of the authors is included exemplarily for the model structure rutile TiO2 presenting the progress in measurement and interpretation.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000337297500008
DO  - DOI:10.1002/crat.201300430
UR  - https://bib-pubdb1.desy.de/record/167546
ER  -