First-Principles Study of Magnetic Properties of 3dTransition Metals Doped in ZnO Nanowires
1 State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing, 100083, People’s Republic of China
2 Department of Physics, School of Sciences, China University of Mining and Technology, Xuzhou, 221008, People’s Republic of China
Nanoscale Research Letters 2009, 4:480-484 doi:10.1007/s11671-009-9260-7Published: 11 February 2009
The defect formation energies of transition metals (Cr, Fe, and Ni) doped in the pseudo-H passivated ZnO nanowires and bulk are systematically investigated using first-principles methods. The general chemical trends of the nanowires are similar to those of the bulk. We also show that the formation energy increases as the diameter of the nanowire decreases, indicating that the doping of magnetic ions in the ZnO nanowire becomes more difficult with decreasing diameter. We also systematically calculate the ferromagnetic properties of transition metals doped in the ZnO nanowire and bulk, and find that Cr ions of the nanowire favor ferromagnetic state, which is consistent with the experimental results. We also find that the ferromagnetic coupling state of Cr is more stable in the nanowire than in the bulk, which may lead to a higherTcuseful for the nano-materials design of spintronics.