XAFS spectra from reflectivity measurements

The reflectivity of TiSi 2 films was measured as a function of photon energy E at the Ti K ‐edge region at a glancing angle θ close to the critical angle θ C of total reflection. TiSi 2 silicide films (about 30 nm thickness) were prepared by silicidation of Ti thin films deposited on Si(001) substrates. Since the Fresnel reflectivity R (θ, E ) is a function of the dispersion δ( E ) and of the absorption β( E ), the absorption β( E ) which carries the XAFS signal can be solved as β(θ,δ, R ) for observed reflectivity R and for estimated δ. The dispersion δ( E ) is related to the absorption β( E ) by the Kramers–Kronig (K–K) relations since the refractive index is n ( E ) = 1 −δ( E ) − i β( E ). β( E ) was calculated from the observed reflectivity R (θ, E ) using theoretical values for initial δ( E ). Titanium K ‐edge XAFS for TiSi 2 was extracted from the reflectivity by `ReflXAFS'.