X-ray-absorption spectroscopy of CoSi2.

Abstract

X-ray-absorption near-edge structure (XANES) spectra of thin-film ${\mathrm{CoSi}}_{2}$ were measured at the Si K edge and Co ${\mathit{L}}_{3}$ edge using the total electron yield mode. The Si K-edge results for ${\mathrm{CoSi}}_{2}$ showed a dramatic reduction of intensity in the first broad feature accompanied by a rise in a relatively strong and sharp feature at higher binding energies when compared to XANES spectra for crystalline Si. We attribute these two features to the Si 1s photoelectron excitations to a broad Si 3p nonbonding band and a relatively narrow band of hybridized Si p--Co 3d antibonding states, respectively. Analysis of the Co ${\mathit{L}}_{3}$-edge white line spectra for ${\mathrm{CoSi}}_{2}$ reveals the appearance of a triple structure, which can be attributed to excitations to the unoccupied Co 3d nonbonding states and hybridized antibonding Co (3d,4s)--Si p states. \textcopyright{} 1996 The American Physical Society.