Synthesis and Investigation of Optical and Magnetic Properties of Co-Doped effect on Zinc Oxide Nanoparticles

In this study, the effect of simultaneous doping of magnesium, calcium, and copper ions on the properties of zinc oxide doped with cobalt was investigated. The sol-gel method has been used for the synthesis of nanoparticles. The structural and optical properties of the synthesized nanoparticles were investigated using X-ray diffraction (XRD), infrared spectroscopy (FTIR), and DRS spectroscopy. Rietveld’s analysis of XRD patterns confirmed the hexagonal wurtzite phase structure. In infrared spectroscopy, bands related to this structure were detected at a wavenumber of about 400 cm-1. Microscopic images showed that fine zinc oxide particles with dimensions of 10 to 20 nm were agglomerated by sticking to each other. In addition, it was found that the bandgap of the doped samples was reduced relative to pure zinc oxide. Due to the addition of cobalt as a dopant, the bandgap energy reduced from 3.0 eV to 2.5 eV. Also, copper ion as a second dopant in the composition caused a further reduction in the bandgap and reaches about 2.1 eV. The examination of the samples by the VSM device showed that the magnetic properties of the particles are enhanced by the addition of cobalt dopant and reach 40 memu / g. However, as a result, the magnetic property is reduced with other co-doped samples. copper and cobalt co-doped zinc oxide have no significant changes in magnetic properties. Therefore, with a lower bandgap and the best magnetic properties, this sample can be considered the most suitable sample in the dilute magnetic semiconductors’ application.