Investigations of Mn introduced structural modifications on Ni-doped ZnO diluted magnetic semiconductors and improved magnetic and antibacterial properties

Abstract

Zn0.98Ni0.02O (Z1), Zn0.97Ni0.02Mn0.01O (Z2), and Zn0.96Ni0.02Mn0.02O (Z3) NPs had been synthesized by the co-precipitation method. The X-ray diffraction spectra revealed that synthesized NPs exhibited hexagonal wurtzite structure. At initial Mn concentration, Mn co-doping alters the cell parameter ‘a’ alone, while there was no change in ‘c’. The morphology of NPs was analysed using FESEM analysis and chemical compositions were confirmed through EDAX spectra. The valence state and composition of Zn, Mn, Ni, and O elements at the surface of Z3 NPs were analysed by XPS. FTIR spectra showed that the absorption corresponding to Zn–O stretching had been observed around 442 cm−1 and the peak was shifted towards a higher wavenumber side by Mn co-doping. A UV emission corresponding to NBE and defects related to visible emission were noticed in the photoluminescence spectra. The simultaneous addition of Ni and Mn enhanced the magnetization by increasing the charge carrier density and by controlling the interstitial Zn density. Antibacterial tests were carried out against (G+) S. aureus and (G-) E. coli bacterial strains and all NPs inhibited the bacterial growth.