Magnetic states at the Oxygen surfaces of ZnO and Co-doped ZnO

Abstract

First principles calculations of the O surfaces of Co-ZnO show that substitutional Co ions develop large magnetic moments which long-range coupling depends on their mutual distance. The local spin polarization induced at the O atoms is three times larger at the surface than in the bulk, and the surface stability is considerably reinforced by Co. Moreover, a robust ferromagnetic state is predicted at the Oxygen (0001) surface even in the absence of magnetic atoms. The occurrence of surface magnetic moments correlates with the number of {\it p}-holes in the valence band of the oxide, and the distribution of the magnetic charge is, even in the absence of spin-orbit interaction, highly anisotropic.

References in corpus (7)

• Magnetic effects at the interface between nonmagnetic oxides
• Ferromagnetism as a universal feature of nanoparticles of the otherwise nonmagnetic oxides
• Induced Magnetic Ordering by Proton Irradiation in Graphite
• Two magnetic regimes in doped ZnO corresponding to a dilute magnetic semiconductor and a dilute magnetic insulator
• Magnetic interactions in transition metal doped ZnO : An abinitio study
• $\pi$-Electron Ferromagnetism in Metal Free Carbon Probed by Soft X-Ray Dichroism
• Origin of ferromagnetism in (Zn,Co)O from magnetization and spin-dependent magnetoresistance