Capping ZnO nanoparticles doped with 2% Zn

Fe

Mn and Co ions

respectivety

were grown by separately decomposing the mixtures of Zn and Fe

Mn

Co cupferrates in organic solvent at 200℃ under protection of N2.The nanoparticle structure

morphology

optical and magnetic properties were characterized by X-ray diffraction

transmission electron microscope

absorption spectroscopy

photoluminescence spectroscopy and superconducting quantum interference device magnetometer.The concentration of doped ions was measured by electron dispersion spectroscopy and the measured concentration was consistent very well with that in the mixed precursors.Both pure and Fe

Mn or Co doped ZnO nanoparticles are spherical.The average sizes of pure ZnO nanoparticles is 8.5 nm

Mn dope ZnO nanoparticles 12 nm

Fe doped ZnO nanoparticles 14nm and Co doped ZnO nanoparticles 15 nm.Two kinds of precursors were introduced and heterogeneous nucleation occurred during formation of doped ZnO nanoparticles.Enlargement of the doped ZnO nanoparticle sizes indicated that Mn-O

Fe-O and Co-O produced by precursor decomposing actes as crystal nucleus during heterogeneous nucleation.Only sharp diffraction of wurtzite ZnO phase was observed in Fe

Mn or Co doped nanoparticles.The doped nanoparticles has a good crystal structure.Exciton absorption of ZnO at 3.47 eV and a broadened band of transitional metal d-d absorption at lower energy were observed.The photoluminescence of nanocrystals doped with Mn and Fe ions is similar.The luminescence is consistent of sharp emission of exciton at 3.30 eV

broaden emission of near band at 3.18 eV and emission related with defects at 2.94 eV.The nanoparticles doped with Co ions has strong near band emission at 3.14 eV and very weak defect emission at 2.73 eV.All nanoparticles show strong ultraviolet emission.The field-cooled and zero-field-cooled magnetization of Mn

Fe doped ZnO taken at 1.19×10

3

H show no deviation when the temperature is higher than 40 K and the deviation temperature is 43 K in Co doped ZnO nanoparticle.The magnetization of Co doped nanoparticles is larger than that of Fe and Mn doped nanoparticle.All doped nanoparticls show paramagnetic behavior at room temperature.