“Dopants Incorporation in ZnO Mechanical Milled Powders Sensed By Positrons”

L. C. DAMONTE; V.DONDERIS; J.OROZCO; M.A.HERNÁNDEZ-FENOLLOSA

Foz de Iguazú, Brasil

Conferencia; XIV International Conference on Hyperfine Interactions (HFI+NQI 2007),; 2007

UNLP-CBPF-

Structural and optical characterization of M-doped ZnO (M: Cd, Mg) powders obtained by mechanical milling are present. The starting materials were commercially ZnO, MgO and CdO powders at different concentrations. The samples were prepared by mechanical milling in a Restch MM 2 horizontal oscillatory ball mill. The milled powders were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), positron lifetime annihilation spectroscopy (PALS) and photoluminescence spectroscopy (PL). The mixing of the oxides is followed by means of XRD and SEM. As milling proceeds a clear reduction of grain size and homogenization are observed. The evolution of annihilation parameters and PL spectra with milling time and cation content were analyzed and related with the kind of mechanical induced defect involved. Ternary oxides Zn1−xMxO were efficiency obtained for certain compositions. Different positron traps, as vacancies, interstitials, vacancy clusters were identified during milling evolution. The results showed that positrons constitute a well suited probe to characterize the cation substitution in the ZnO oxide lattice. were efficiency obtained for certain compositions. Different positron traps, as vacancies, interstitials, vacancy clusters were identified during milling evolution. The results showed that positrons constitute a well suited probe to characterize the cation substitution in the ZnO oxide lattice. 1−xMxO were efficiency obtained for certain compositions. Different positron traps, as vacancies, interstitials, vacancy clusters were identified during milling evolution. The results showed that positrons constitute a well suited probe to characterize the cation substitution in the ZnO oxide lattice.