Half-metallic ferromagnetism in Cu doped ZnO?
Abstract
It has been shown that diluted magnetic semiconductors could form by hole doping into ZnO(T.Dietl, et al.,) Science 287, 1019(2000). In this work doping by non-magnetic Cu into ZnO has been simulated by the accurate ab initio FLAPW method(E.Wimmer, H.Krakauer, M.Weinert, and A.J.Freeman, Phys. Rev. B 24), 864(1981), and references therein, using GGA to represent the exchange-correlation potential. For a 1/8 doping concentration which is simulated by a 16 atom supercell, we find magnetic moments of 0.58 μB on Cu, and 0.08 μB or 0.05 μB on neighboring O. Decreasing the doping concentration to 1/16 causes the magnetic moments change by 0.005 μ_B. In the ferromagnetic (FM) phase, the system is half-metallic. The hole states on the Fermi surface are mainly determined by Cu 3d and O 2p hybridization. The calculated exchange splitting is 0.45 eV which opens a half-metallic gap of 0.30 eV. For comparison with the FM phase, several anti-ferromagnetic (AFM) phases are being investigated using the doubled supercell. To design possible diluted magnetic semiconductors, simulations of doping by other non-magnetic ions into ZnO are also in progress.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARL26014Y