Spin-dependent tunneling from clean and oxidized Co surfaces

Authors

Kirill D. Belashchenko, University of Nebraska-LincolnFollow
Evgeny Y. Tsymbal, University of Nebraska-LincolnFollow
Mark van Schilfgaarde, Arizona State UniversityFollow
Derek A. Stewart, Sandia National LaboratoriesFollow
I. I. Oleynik, University of South Florida
Sitaram S. Jaswal, University of Nebraska-LincolnFollow

Date of this Version

2004

Document Type

Article

Citation

Journal of Magnetism and Magnetic Materials 272–276 (2004) 1954–1955

Comments

U.S. Government Work

Abstract

Transmission through a sufficiently thick vacuum barrier is factorized in the product of two ‘‘surface transmission functions’’ and a vacuum decay factor. Based on this factorization, we study the spin polarization of the tunneling current from clean and oxidized (1 1 1) FCC Co surfaces through vacuum into Al. The conductance is calculated using the principal-layer Green’s function approach within the tight-binding LMTO scheme. We find that for typical vacuum barrier thicknesses the tunneling current from the clean surface is dominated by minority-spin electrons. A monolayer of oxygen on top of the surface completely changes the shape of k_ll-resolved transmission and makes the tunneling current almost 100% majority-spin polarized.