Multiple-scattering EXAFS and EXELFS of titanium aluminum alloys

The extended fine structure of K edges of binary intermetallic compounds Ti Al, Ti3Al, and Al3Ti have been recorded by x-ray absorption spectroscopy (X AS) at the Ti K edge and by electron energy-loss spectroscopy (EELS) at the Al K edge. The local structure of these titanium aluminum alloys is fully resolved by combining the information retrieved from a spectral analysis of both XAS and EELS data. The data analysis is based on fits to ab initio ca lculations using the real-space multiple scattering code FEFF. It is shown that XAS and EELS can be considered as probes for medium range order studie s. This is illustrated for TiAl compounds where it is found that XAS and EE LS can be used for site determination of minor elements in ternary dilute a lloys. The limitations of this multiple data set approach to fine-structure spectroscopies are briefly discussed.