A study on the microstructural parameters of Zn _(1-x)La_xZr_xO nanopowders by X-ray line broadening analysis

In the present study, the pure and La-Zr co-doped ZnO nanoparticles were prepared by sol-gel technique using zinc acetate dehydrate (Zn(Ac)₂ ·₂H₂ O), lanthanum nitrate hexahydrate (La(NO₃)₃ ·6H₂O) and zirconium chloride (ZrCl₄ ) as precursor. The structure and morphology of the prepared nanoparticle samples were studied using X-ray diffraction and transmission electron microscopy measurements. X-ray diffraction results indicated that all the samples have crystalline wurtzite phase. TEM showed that powder was polycrystalline in nature with random distribution of the pure and La-Zr doped ZnO nanoparticles. We demonstrate strain-size evaluations for pure and doped ZnO nanoparticles from the x-ray line profile analysis. The microstructural effects of crystalline materials in terms of crystallite sizes and lattice strain on the peak broadening were investigated using Williamson-Hall (W-H) analysis and size- strain plot (SSP) method. The average crystallite size of Zn _(1-x)La_x Zr_x O nanoparticles estimated from the W-H analysis and SSP method varied as the doping concentration increased. The incorporation of Zr⁴⁺ ion in the place of Zn^₂₊ caused an increase in the size of nanocrystals as compared to undoped ZnO. The average particle sizes of co-doped ZnO nanoparticles estimated from the USDM model is in good agreement with the TEM results. (author)