Program Highlights

Spin Polarization at Oxidized Co Surface

Spin-dependent tunneling in magnetic tunnel junctions has garnered much attention due to possible applications in non-volatile random access memories and magnetic field sensors. Using first-principles calculations and quantum theory of transport we have studied spin-dependent tunneling from the oxidized Co surface. The results show that adsorption of a monolayer oxygen at the Co surface changes sign of the spin polarization due the antibonding Co-O surface states. The sensitivity of the spin polarization to the interface structure and bonding broadens dramatically the possibilities to engineer magnetic tunnel junctions with properties desirable for device applications.

Kirill Belashchenko, Evgeny Tsymbal and Sitaram Jaswal

Minority-spin density of electronic states within the surface Brillouin zone for bulk Co and the oxidized Co surface.