Investigation of thickness dependence on electronic structures of iron and nickel thin films by L-edge X-ray absorption spectroscopy

Abstract

We have studied the effect of the film thickness on the electronic structure of pure nickel and iron thin films. Series of the thin films were evaporated by e-beam evaporation on SiN substrates. The electronic structure of the thin films was investigated using X-ray absorption near edge structure (XANES) spectroscopy. We have showed the thickness dependent variation of the experimental branching ratio (BR) and full-width at half-maximum (FWHM) at the L3 and L2 edges for both thin films. A strong thickness dependence of the L2,3 BR and FWHM was found. We have also focused on the deviation of L3 to L2 ratio from its statistical value. The average L3/L2 white-line intensity ratio was calculated to be 3.4 and 3.0 from peak height and integrated area under each L3 and L2 peaks, respectively for iron. Additionally, a theoretical L2,3 edge calculation for nickel was presented. The obtained results were consistent with the general view of the L2,3 BR and FWHM of iron and nickel transition metals.