Influences of Co doping on the structural and optical properties of ZnO nanostructured

King Saud University Department of Physics and Astronomy Riyadh 114 51 Saudi Arabia
Applied Physics A (Impact Factor: 1.69). 100(1):45-51. DOI: 10.1007/s00339-010-5840-8

ABSTRACT Pure and Co-doped ZnO nanostructured samples have been synthesized by a chemical route. We have studied the structural and
optical properties of the samples by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), field-emission
transmission electron microscope (FETEM), energy-dispersive X-ray (EDX) analysis and UV–VIS spectroscopy. The XRD patterns
show that all the samples are hexagonal wurtzite structures. Changes in crystallite size due to mechanical activation were
also determined from X-ray measurements. These results were correlated with changes in particle size followed by SEM and TEM.
The average crystallite sizes obtained from XRD were between 20 to 25 nm. The TEM images showed the average particle size
of undoped ZnO nanostructure was about 20 nm whereas the smallest average grain size at 3% Co was about 15 nm. Optical parameters
such as absorption coefficient (α), energy band gap (E

), the refractive index (n), and dielectric constants (σ) have been determined using different methods.

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