Electronic and Magnetic Structures in O/Cr(001) Surface from Angle-Resolved Photoemission Spectroscopy

Abstract

We measured the angle-resolved photoemission spectra of Cr(001) surface with and without oxygen adsorption to study the surface and interfacial electronic structures in relation to its magnetism. The experimental results show that the surface states and Cr 3 d –O 2 p interfacial state are found near the Fermi level, and they are responsible to the surface ferromagnetism of Cr(001). The energy band dispersion of this interfacial state indicates the odd symmetry with respect to the mirror plane (010), and originates from the 3 d x y –2 p y antibonding state. It was found that the fully occupied antibonding state leading to the negative surface relaxation results in the enhancement of magnetic moments in O/Cr(001). This magneto-volume effect also realized that the energy band width of O/Cr(001) is at most 50% less than that of clean Cr(001) surface.