Investigation of Local Structure of Novel Materials using EXAFS Technique

The orientation-dependent structural properties of Zn(1-x)Mg(x)O nanorods with different Mg concentrations were investigated quantitatively using polarization-dependent extended X-ray absorption fine structure (EXAFS) measurements at the Zn K edge. Vertically-aligned Zn(1-x)Mg(x)O nanorods were synthesized on Si substrates using catalyst free metal organic chemical vapor deposition. Polarizatio...

Silver K edge extended X-ray absorption fine structure (EXAFS) spectroscopy of films containing silver behenate (AgBeh) in the unprocessed, fully processed, and step-processed states has been performed. The results of the EXAFS analysis indicate that the intensity for the real-space peak for the Ag-O distance (~2.3 Å) decreases while the real-space peak for the AgAg distance (~2.9 Å) grows with...

The Ti K-edge EXAFS for PbTiO3 measured in the temperature range including the critical temperature (763K) due to the phase transition from tetragonal to cubic phase is discussed from the local point of view. Three kinds of atomic pairs, shorterTi-O(1),mediumTi-O(2) and longerTi-O(3)were analyzed independently. The interatomic distance of Ti-O(3) changes at Tc discontinuously and shows a “displ...

We use differential extended X-ray absorption fine structure (Δ-EXAFS) to monitor the Ar-induced surface restructuring of silica-supported Pd nanoclusters (1 nm diameter) at 77 K. Δ-EXAFS analysis shows 9 ± 2 nearest-neighbor Pd-Pd bonds expand by 0.104 ± 0.005 Å as a result of Ar adsorption. Atomistic molecular dynamics simulations provide evidence for a model in which Ar drives restructuring ...

The proximity of Ca to the Mn cluster of the photosynthetic water-oxidation complex is demonstrated by X-ray absorption spectroscopy. We have collected EXAFS data at the Ca K-edge using active PS II membrane samples that contain approximately 2 Ca per 4 Mn. These samples are much less perturbed than previously investigated Sr-substituted samples, which were prepared after Ca depletion. The new ...

A novel approach for the analysis of extended X-ray absorption fine structure (EXAFS) spectra is developed exploiting an inverse machine learning-based algorithm. Through this approach, it possible to explore and account for, in a precise way, nonlinear geometry dependence photoelectron backscattering phases amplitudes single multiple scattering paths. In addition, determined parameters are dir...