Biosynthesis and characterization of CaZrO_3 nanoparticles via hyphaene thebaica: effect of preparation method on morphology, electrical, and dielectric properties

摘要

CaZrO_3 nanoparticles were synthesized by biosynthesis process via Hyphaene thebaica natural extract as a reducing and stabilizing agent. The crystalline structure and vibration modes of CaZrO_3 were investigated by X-ray diffraction and Raman spectroscopy. Their optical properties were studied using ultraviolet-visible diffused reflectance spectroscopy and photo-luminescence spectroscopy. In order to study the effect of the synthesis method and the reduction of the grain size on the morphology and the electrical and dielectric properties of the material, the results obtained for CaZrO_3 synthesized by the biosynthesis process were compared to those obtained for CaZrO_3 prepared by the conventional solid-state method. Transmission electron microscopy shows a marked improvement in the morphology of the compound synthesized by the biosynthesis process compared to that prepared by the solid-state reaction. The ionic conductivity of both samples was measured using the electrochemical impedance technique. It was found that the contribution of grain boundary resistance to total resistance has increased significantly with size reduction and led to the improvement of the dielectric properties of the material by the increase of dielectric constant and the decrease of dielectric loss.