In this study, we present a framework for characterizing the structural and thermal properties of small nanoparticle catalysts by combining precise synthesis, extended X-ray absorption fine structure (EXAFS) spectroscopy, and density functional theory (DFT) calculations. We demonstrate the capability of this approach by characterizing the atomic structure and vibrational dynamics of Au147. With...

with appropriate accomodation for forward scattering (\focussing e ect") for higher shells, and inclusion of higher cumulants as necessary. The aim of data analysis is to determine the distances, coordination numbers, disorder parameters and types of atoms in the various coordination shells for the \unknown" sample. The extent to which this is possible depends on the nature of the system, the q...

In this paper, the temperature-dependent extended X-ray absorption fine structure (EXAFS) of distorted crystalline cadmium has been analyzed using an efficient calculation-model. The analysis procedure is based on evaluating influence temperature phase shift and amplitude reduction EXAFS oscillation that expressed in terms Debye-Waller factor. anharmonic cumulants are calculated by expanding co...

the date of receipt and acceptance should be inserted later Abstract. We have investigated the local atomic structure of amorphous TM-Ti alloys (TM = Co, Ni, Cu) produced by Mechanical Alloying by means of EXAFS analyses on TM and Ti K-edges. Coordination numbers and interatomic distances for the four alloys where found and compared. EXAFS results obtained indicated a shortening in the unlike p...

The metallic Co catalyst for the Fischer-Tropsch reaction is prepared by reduction of Co salts impregnating microporous silica. The average size of the metallic Co clusters is determined from the average number of neighbours deduced from Co K-edge EXAFS of catalyst samples. A model EXAFS signal constructed from the scattering paths of Co metal fcc lattice with lengths up to 5 A is calibrated on...

A new approach to the extraction of dynamic information from extended X-ray absorption fine-structure (EXAFS) spectra has been developed. With this method, a complete set of temperature-dependent spectra are fit simultaneously to one of a variety of pair-distribution functions. Distributions are calculated in r-space using the appropriate absorber-scatterer pair potential. The temperature-depen...

We demonstrate that the temperature dependence of structural as well as magnetic uctuations can be probed by the use of the Magnetic Extended X-ray Absorption Fine Structure (MEXAFS) spectroscopy. We compare those to the dynamic disorder as probed by the EXAFS. Here we present temperature-dependent MEXAFS investigations carried out at the L-edges of a thin Fe lm and a Gd single crystal. By comp...

A large number of AgI-based fast-ion-conducting glasses have been investigated by K-iodine extended x-ray absorption fine structure spectroscopy (EXAFS) measurements at liquid nitrogen temperature. A general correlation between the I-Ag distance measured by EXAFS and the glass activation energy for dc ionic conductivity has been found out: glasses with longer I-Ag distances display higher ionic...

T. Yokoyama 2 and K. Eguchi (IMS, The Grad. Univ. for Adv. Stud.) Thermal expansion of a tetragonal Mn88Ni12 alloy, which exhibits significant anisotropy, was investigated by EXAFS and path-integral quantum mechanical simulations. The EXAFS reveals that the Mn local environment is actually tetragonally distorted, while the Ni one retains its inherent cubic-like symmetry. The large thermal expan...

Department of Chemistry and INSTM Refe Giuria 7, 10125 Turin, Italy. E-mail: carlo.l NIS Centre of Excellence, University of Turi Haldor Topsøe A/S, Nymøllevej 55, 2800 Kg CrisDI Center of Crystallography, Universit Southern Federal University, Zorge street 5 † Electronic supplementary information (sample description, in situ FTIR spectr DFT-based analysis of XAS and XES reversibility of the Cu...