We present an analysis of the structural, electronic, and magnetic properties of nitrogen-doped ZnO nanowires (hexagonal and triangular shapes) as obtained by means of density functional theory calculations. We found that the lattice distortions induced by the presence of neutral defects are negligible in most doping cases and that the energy of the acceptor levels generated by nitrogen depends on the positions of the dopant within the nanowire and on its diameter. Both in hexagonal and triangular nanowires, the defect formation energy decreases when going from the bulk to the surface of the wire; thus, impurities tend to segregate at the surface of the nanostructure. The study of the ferromagnetic stability of the doped systems points to a spin-polarized ground state, particularly in the case of surface doping. Furthermore, a long-range magnetic coupling between dopants that oscillates between ferromagnetic and antiferromagnetic ordering as a function of the defect-defect distance within the nanowire was observed. The striking feature is that such coupling is likely sp, in which the d orbitals of zinc are not involved.
Effect of nitrogen impurities on the physical properties of ZnO nanowires: First-principles study / Haffad S.; Samah M.; Cicero G.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - ELETTRONICO. - 85(2012), p. 165207. [10.1103/PhysRevB.85.165207]
|Titolo:||Effect of nitrogen impurities on the physical properties of ZnO nanowires: First-principles study|
|Data di pubblicazione:||2012|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevB.85.165207|
|Appare nelle tipologie:||1.1 Articolo in rivista|
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