Spin-polarized Shockley state at free surface and at - -based structures on surfaceL. Magaud1, A. Pasturel2, P. Mallet1, S. Pons1, 3 and J.-Y. Veuillen1
1 LEPES-CNRS - BP 166, 38042 Grenoble cedex 9, France
2 LPM2C-CNRS - BP 166, 38042 Grenoble cedex 9, France
3 IPN, EPFL - 1015 Lausanne, Switzerland
(Received 4 February 2004; accepted in final form 16 April 2004)
The electronic structure of and free surfaces and of - structures on the (111) surface is studied from ab initio calculations. Systems ending on a layer are found to be magnetic. The spin splitting of the d band raises the position of some minority dxz,yz states which then lie in the energy range where the Shockley state should appear. This results in a strong sp- d hybridization of the spin-down components which furthermore depends on the k momentum. As a result, the Shockley state of -terminated surfaces is spin polarized. The ab initio results are compared to recent STM experiments.
73.20.At - Surface states, band structure, electron density of states.
71.20.Be - Transition metals and alloys.
71.15.Mb - Density functional theory, local density approximation, gradient and other corrections.
© EDP Sciences 2004