Effects of Gd ions doping on the microstructural, magnetic and optical properties in ZnO nanocrystals

This article reports the structural, magnetic and optical responses of Gd ion-substituted ZnO nanoparticles prepared via soft chemical co-precipitation technique. Both the hexagonal wurtzite crystal structure and crystallographic phase purity of all the samples were observed by using X-ray diffraction (XRD) technique. Three widely accepted methods, i.e., Scherrer’s approach, Williamson–Hall plot and Halder–Wagner method, have been used to determine the average crystallite size and microstrain within the nanosized ZnO crystals. Average crystallite size was obtained within the range of 23 ± 3 nm. Mean particle size obtained from HRTEM image was also found in good harmony with the XRD results. UV–visible spectra signified that all the nanosized ZnO samples manifested strong absorption in between 410 and 455 nm. The presence of both Zn and O vacancies in the samples was verified by the photoluminescence studies. Paramagnetic response of Gd ions in ZnO nanoparticles weakened the defect-driven magnetic behaviour at room temperature.