title: Fluorescence detection of white-beam X-ray absorption anisotropy: towards element-sensitive projections of local atomic structure.
abstract: Projections of the atomic structure around Nb atoms in a LiNbO(3) single crystal were obtained from a white-beam X-ray absorption anisotropy (XAA) pattern detected using Nb K fluorescence. This kind of anisotropy results from the interference of X-rays inside a sample and, owing to the short coherence length of a white beam, is visible only at small angles around interatomic directions. Consequently, the main features of the recorded XAA corresponded to distorted real-space projections of dense-packed atomic planes and atomic rows. A quantitative analysis of XAA was carried out using a wavelet transform and allowed well resolved projections of Nb atoms to be obtained up to distances of 10 Å. The signal of nearest O atoms was detected indirectly by a comparison with model calculations. The measurement of white-beam XAA using characteristic radiation indicates the possibility of obtaining element-sensitive projections of the local atomic structure in more complex samples.
authors: Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland. pawel.korecki@uj.edu.pl
authors: P
authors: P
authors: Korecki
authors: M
authors: M
authors: Tolkiehn
authors: K M
authors: KM
authors: Dąbrowski
authors: D V
authors: DV
authors: Novikov