Density functional study of magnetic properties in Zn-doped SnO2

Magnetic properties in Zn-doped SnO2 are examined through the first-principles electronic structure calculations based on density functional theory. Our results reveal that Zn-doping induces localized spin magnetic moments primarily on the first coordination shell of O atoms surrounding the Zn atom as well on Zn atom with total magnetic moment of 1.47 mu(B) per supercell. Holes localized on O atoms in ZnO6 are polarized with the same spin orientation as that of the dopant. Ferromagnetic coupling between Zn ions in Zn-doped SnO2 is attributed to the hole-mediated p-d exchange coupling interaction. With respect to native defects in Zinc-doped SnO2, formation of oxygen vacancy (V-O) is suppressed whereas formation of tin vacancy (V-Sn) is facilitated due to Zn-doping. It is found that the observed ferromagnetism in Zn-doped SnO2 mainly originates from the Zn dopant rather than exclusively the formation of V-Sn. (C) 2010 American Institute of Physics. [doi:10.1063/1.3503224]