Structural and optical characterization of Sm-doped ZnO nanoparticles

Abstract

Micro-structural changes in zinc oxide (ZnO) nanoparticles induced by the substitution of Zn 2+ in ZnO by a rare earth (RE) metal ion, Sm 3+ , are investigated. Both pristine and Sm-doped ZnO with a nominal doping concentration of 1, 2 and 4% of Sm using a simple wet-chemical synthetic route followed by calcination at a high temperature of 900 • C, are synthesized. Structural investigations are primarily conducted using X-ray powder diffraction (XRPD) and scanning electron microscopy techniques. Evolution of structural parameters (unit cell parameters, average crystallite size, crystallinity percentage, lattice strain, stress, energy density and atomic packing factor) upon Sm doping is investigated together with Rietveld refinement and Le Bail analysis techniques. XRPD data confirmed that the synthesized nanostructures crystallize in a wurtzite hexagonal structure, the dopant Sm is incorporated into the Zn lattice and the annealing treatment plays a crucial role in determining the structural and optical properties of RE-metal-doped nanoparticles. Values of the optical band gap energy estimated from optical absorbance measurements reveal a widening of the band gap.

Influence of Metal (Al, Mg, Sm, and Cu) Dopants on Structural, Optical, Magnetic, and Antimicrobial Properties of ZnO Nanopowders Synthesized by Coprecipitation Method

“…Echresh et al [ 34 ] reported that lattice constants enhance for Al‐doped ZnO nanoparticles in comparison to ZnO nanoparticles. Okur et al [ 35 ] reported that lattice parameters increase for Sm‐doped ZnO nanoparticles when compared with ZnO nanoparticles. Le et al [ 36 ] also reported that lattice constants increase for Sm‐doped ZnO as compared to the ZnO thin films.…”

Exploring the Defects and Vacancies with Photoluminescence and XANES Studies of Gd3+‐Substituted ZnO Nanoparticles

“…This parameter is also found to increase with Gd doping. The replacement of Gd ions at Zn ion positions also alters the ZnO bond length ( L ) which may be calculated with following formula [ 31 ] $$\[ \begin{array}{*{20}{c}}{L = \sqrt {\left( {\frac{{{a^2}}}{3} + {{\left( {\frac{1}{2} - u} \right)}^2}{c^2}} \right)} }\end{array} \]$$where u is the wurtzite structure's positional parameter that is determined with equation [ 29 ] $$\[ \begin{array}{*{20}{c}}{u = \frac{{{a^2}}}{{3{c^2}}} + \,0.25}\end{array} \]$$…”

“…This parameter is also found to increase with Gd doping. The replacement of Gd ions at Zn ion positions also alters the ZnO bond length (L) which may be calculated with following formula [31] 3…”

Solution Processed Zn1−x−ySmxCuyO Nanorod Arrays for Dye Sensitized Solar Cells

“…This indicates that the drop in (002) diffraction peak is due to the replacement of Cu 2+ /Sm 3+ ions in Zn 2+ ions, which restrains the crystal growth of ZnO [ 38 ]. Therefore, doping of Cu 2+ /Sm 3+ may act as an inhibitor for the growth of ZnO along the (002) plane [ 39 ]. The same inhibitory trend in crystal growth was also enumerated in other transition and rare earth ions doped ZnO thin films.…”