Speaker
Ms
WINFRED MUENI MULWA
(UNIVERSITY OF THE FREE STATE PRIVATE BAG X13 PHUTHADITJHABA, 9866)
Description
Key words: Semiconductors, Electronic structure, Magnetic Properties, Optical properties
Abstract: Ce3+, Cu2+ co-doped ZnO (Zn1_2xCexCux O: x¼0.00, 0.01, 0.02, 0.03, 0.04 and 0.05) nanocrystals were synthesized by the use of sol-gel technique. These nanocrystals were investigated by using X-ray diffraction (XRD), UV–visible diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), High-resolution transmission electron microscope (HR-TEM) and selected area electron diffraction (SAED). The stability and magnetic properties of Ce3+ and Cu2+ co-doped ZnO were probed by first principle calculations. XRD results revealed that all the compositions are single crystalline, hexagonal wurtzite structure. The optical band gap of pure ZnO was found to be 3.22 eV, which was in agreement with other experimental findings [1, 2] and it decreased from 3.22 to 3.10 eV with an increase in the concentration of Cu2+ and Ce3+ content. The morphologies of Ce3+ and Cu2+ co-doped ZnO samples confirmed the formation of nanocrystals with an average grain size ranging from 70 to 150 nm. The ab initio magnetization calculations results affirmed the antiferro and ferromagnetic state for Ce3+ and Cu2+ co-doped ZnO structure.
Reference: [1] J.F. Chang, W.C. Lin, M.H. Hon, Appl. Surf. Sci. 183 (2001) 18.
[2] I. Djerdj, Z. Jaglicic, D. Arconde, M. Niederberger, , Nanoscale 2 (2010) 1096.
Apply to be<br> considered for a student <br> award (Yes / No)?
YES
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
PhD
Summary
Ce, Cuco-dopedZnOnanocrystals
weresuccessfullysynthesizedbya
microwavecombustionmethod.
With Ce–Cu co-doping,crystallite
size, latticeparametersandstrainof
ZnO changes.
The bandgapofthesynthesized
samples hasbeenvariedintherange
of 3.15–3.10eV.
The grainsizeofthesampleisde-
creased withtheincreaseinCe–Cu
co-doping.
The magnetizationmeasurements
result intoferroandantiferromag-
netic stateforallco-dopedsamples
which isinagreementwith first
principles theoreticalcalculations
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
YES
Main supervisor (name and email)<br>and his / her institution
Prof. Dejene Birhanu Francis
DejeneBF@ufs.ac.za
Department of Physics
University of the Free State- Qwaqwa campus
Private Bag X13 Phuthaditjhaba 9866
South Africa
Primary author
Ms
WINFRED MUENI MULWA
(UNIVERSITY OF THE FREE STATE PRIVATE BAG X13 PHUTHADITJHABA, 9866)
Co-author
Prof.
FRANCIS BIRHANU DEJENE
(UNIVERSITY OF THE FREE STATE PRIVATE BAG X13 PHUTHADITJHABA, 9866)
