EXTENDED X-RAY ABSORPTION FINE-STRUCTURE STUDIES OF IBS FE-TB ALLOY-FILMS

We have employed extended x-ray absorption fine structure (EXAFS) analysis to study the compositional dependence of the atomic structure in Fe-Tb alloy films. Fourier transforms of EXAFS data, relative to both the Fe K and the Tb L(III) absorption edges, provide information about the local atomic environments relative to each atom. Results indicate the Fe EXAFS data to be dominated by Fe-Fe correlations, and consists of contributions from two Fe atomic shells at radial distances near 2.47 and 2.66 angstrom and a Tb shell near 2.91 angstrom. The coordination number of the Fe shells are measured to increase, while radial distances decrease, with increased Fe content. The Tb EXAFS data was found to have an atomic shells of Fe and Tb at 2.91 and 3.47 angstrom, respectively. Analysis suggests that the Fe shell is very disordered and is comprised of approximately 9.5 atoms while the Tb shell has almost-equal-to 3 atoms.