Original Research Papers
Structural and Optical Characterization of Ni and Al Co-Doped ZnO Nanopowders Synthesized via the Sol-Gel Process
2015 Volume 32 Pages 154-162
Details
2015 Volume 32 Pages 154-162
We have successfully synthesized (Ni,Al) co-doped ZnO nanostructured powders via the sol-gel technique at low temperature. The elemental analysis confirms the incorporation of the Ni and Al ions into the ZnO matrix. The structural study revealed that the nanopowder samples are assembled in flower-shaped Zn0.9-xNi0.1AlxO nanostructures with average crystallite sizes ranging from 39 to 53 nm. The XRD patterns show that the Zn0.9-xNi0.1AlxO nanopowders have a hexagonal wurtzite polycrystalline structure. Weak diffraction peaks related mainly to nickel oxides are also detected in the samples. The highest crystallite size, lowest lattice parameters and unit cell volume are obtained for the nanopowder samples that contain 1.5 at.% of aluminum. The decomposition process of the dried gel system is investigated by thermogravimetric analysis (TGA). Raman scattering and FT-IR measurements confirm the wurtzite structure of the synthesized Zn0.9-xNi0.1AlxO nanopowders. The energy band gap of the synthesized nanopowders (~3.32 eV) was estimated by using the Brus equation and the crystallite sizes obtained from XRD data, for comparison. The strain in the nanopowder samples (~2.7 × 10–3) was also calculated according to the Stokes-Wilson equation.
