"X-ray emission spectroscopy and density functional study of CO/Fe(100) "

J. Gladh: H. Öberg, Jibiao Li, M. P. Ljungberg, A. Matsuda, H. Ogasawara, A. Nilsson, L. G. M. Pettersson, and H. Öström; The Journal of Chemical Physics, 01/18/12.

Additional Authors: H. Öberg, Jibiao Li, M. P. Ljungberg, A. Matsuda, H. Ogasawara, A. Nilsson, L. G. M. Pettersson, and H. Öström

Abstract:

We report x-ray emission and absorption spectroscopy studies of the electronic structure of the predissociative α3 phase of CO bound at hollow sites of Fe(100) as well as of the on-top bound species in the high-coverage α1 phase. The analysis is supported by density functional calculations of structures and spectra. The bonding of “lying down” CO in the hollow site is well described in terms of π to π* charge transfer made possible through bonding interaction also at the oxygen in the minority spin-channel. The on-top CO in the mixed, high-coverage α1 phase is found to be tilted due to adsorbate-adsorbate interaction, but still with bonding mainly characteristic of “vertical” on-top adsorbed CO similar to other transition-metal surfaces.