材料期刊网

The g factors and hyperfine structure constants for CdSe:Mn(2+) nanocrystals are theoretically investigated with the perturbation formulae of these parameters for a 3d(5) ion in tetrahedra, by considering both the crystal-field and charge-transfer contributions. The contribution of the charge-transfer mechanism to the g-shift (= g - g(s), where g(s) = 2.0023 is the spin-only value) is opposite (positive) in sign and much larger in magnitude than that of the crystal-field mechanism. Comparatively, the importance of the charge-transfer contribution to the hyperfine structure constant is less significant than it is to the g-shift. That hyperfine structure constants for CdSe:Mn(2+) nanocrystals are larger than those for the bulk is attributed to the larger core polarization constant in the nanocrystals due to the size effect.