Modifying the Structural, Morphological and Dielectric Properties of ZnO Nanoparticles via Co and Ni Doping

Abstract

Pure ZnO and (TM) transition metal-doped ZnO NPs (MXZn1-XO NPs M=Co and Ni with X= 0%, 15%, 25%, 35% and 45%) were prepared by using Sol-gel autocombustion method using metal nitrate precursor and sucrose (bio fuel) followed by annealing at 800°C. The synthesized pure ZnO and doped ZnO nanoparticles were evaluated using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The XRD data revealed that the samples exhibited crystalline characteristics with a hexagonal wurtzite structure. Structural parameters, including lattice constants (a and c), the crystallite sizes (D), volume of the unit cell (V) and microstrain (ε) were determined. SEM results showed more porous and loosely agglomerated nanostructures with increased doping. Compared to Ni²⁺ or pure ZnO, Co²⁺ exhibits a greater spike in polarization, dielectric response and conductivity because of its stronger dorbital interactions. Furthermore, Co and Ni doped ZnO exhibit a higher dielectric loss compared to pure ZnO.