Article

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

King Saud University Chemical Engineering Department Riyadh 114 21 Saudi Arabia; 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

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

0 Bookmarks
 · 
199 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nanosized Cr-doped ZnO particles were synthesized by facile sol-gel method. The structural and optical properties of the particles have been investigated by XRD and FTIR spectroscopy at room temperature for 0, 1 and 5 % concentration of Cr doping. X-ray diffraction analysis reveals that the Cr-doped ZnO crystallizes in a single phase polycrystalline nature with wurtzite lattice. The average crystallite size decreases with increase in Cr concentration (i.e. 33.5 nm for 0 % & 29.7 nm for 1 % and 24.7 for 5 %). FTIR results also indicate the correlation between structural and optical properties of the nanoparticles.
    Asian Journal of Chemistry. 01/2011; 23(12):5622.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The paper presents the optical properties of undoped and aluminium-doped zinc oxide nanostructures grown on glass substrates using the hydrothermal method. The obtained ZnO-based nanostructures showed optical transmittance over 75% and low reflectance in the visible domain. The increasing of optical transmittance of Al-doped ZnO nanostructures with increased doping concentrations was observed. The optical constants such as index of refraction, extinction coefficient, dielectric constants and optical conductivity were determined using the transmission and the reflection at normal incidence of light in the wavelength range of 200–1100 nm. The band gap broadens with increasing dopant concentration from 2% to 4%. The obtained nanostructured layers with size in the range of subwavelength of visible light can act as anti-reflective coating that reduces reflectance based on the Moth Eye principle.
    Optical Materials 01/2012; · 2.08 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The ferromagnetic transparent conducting film is a multifunctional film which has high visible transmittance, low resistivity and room-temperature ferromagnetism, simultaneously. In this article, ferromagnetic transparent conducting ZnO:Al/Fe65Co35/ZnO:Al multilayer films were fabricated by inserting a middle magnetic Fe65Co35 layer into aluminum-doped zinc oxide (ZnO:Al) matrix using a magnetron sputtering apparatus at substrate temperature ranging from room temperature (RT) to 400∘C. The total film thickness was about 400 nm and the middle Fe65Co35 alloy layer was 4 nm. The influences of substrate temperature (T s ) on the structural, electrical, optical and magnetic properties of the multilayer films were systemically investigated. The results showed that the microstructure and performance of the composite multilayer films strongly depended on the substrate temperature. The present results also showed that the inserted middle Fe65Co35 alloy thin layer played an important role in providing the RT ferromagnetism and decreasing the resistivity of the multilayer films. Therefore, it is possible to obtain a multifunctional film material with the combination of good optical transparency, high electrical conductivity and RT ferromagnetism.
    Applied Physics A 106(3). · 1.69 Impact Factor

Full-text

Download
7 Downloads
Available from
Sep 26, 2014