Dy3+ ion-doped lithium nickel nanoparticles: Preparation and investigation of nanomagnetic ferrite for antimicrobial applications

This study investigates the impact of Dy3+ doping in Lithium-Nickel ferrite. Nanoparticles of Dy3+ doped Lithium-Nickel ferrite (Li1.8Ni0.1DyyFe2-yO4) with varying concentrations (y = 0.025, 0.05, 0.075, 0.1, 0.125) have been successfully synthesized using the Sol-Gel auto-combustion technique. Li1.8Ni0.1DyyFe2-yO4 ferrite crystallizes in a spinel cubic structure, although the presence of secondary phases is observed. Various characterization tools, including X-ray diffraction for phase investigation, Vibrating sample magnetometry for magnetic properties, Fourier Transform Infrared Spectroscopy for structural analysis, and Ultraviolet-visible spectroscopy for absorption bands, have been employed in this study. The analysis of X-ray diffraction data reveals that the crystallite size falls within the range of 32.79-11.13 nm. Notably the crystallite size determined using both the Debye-Scherrer formula and the Williamson and Hall plot is in close agreement. The Fourier Transform Infrared Spectroscopy pattern of the synthesized ferrite elucidates the asymmetric stretching mode of the spinel transition in Li1.8Ni0.1DyyFe2-yO4. Additionally, the saturation magnetization for Li1.8Ni0.1DyyFe2-yO4 ranges from 13.7778 to 25.5333 emu/gm. The UV-visible spectra analysis reveals decreased optical band gap energy of LithiumNickel ferrites after Dy3+ doping. Subsequently, the synthesized nanoparticles demonstrate promising antibacterial and antifungal activity, yielding positive results in the conducted tests.