Role of Mn doping to transform ZnLa0.1Fe1.9O4 nanoparticles from antiferromagnetic to ferromagnetic characteristics

Abstract

In the current work, Mn_xZn_1−xLa_0.1Fe_1.9O₄ ferrite nanoparticles were prepared using a solid-state reaction, with x values of 0, 0.1, 0.3, 0.5, 0.7, and 1. The structure, morphology, optical, magnetic, and dielectric characteristics of the prepared samples were characterized using X-ray Diffraction (XRD), Fourier Transformed Infrared Spectrometer (FTIR), Scanning Electron Microscopy (SEM), UV-Vis spectrophotometer, Vibrating Sample Magnetometer (VSM) and impedance analyzer. XRD and FTIR spectra assured the formation of the cubic spinel phase structure as well as tetrahedral and octahedral bonding in the synthesized samples. SEM analysis of the surface morphology revealed irregular and semi-spherical shapes. The prepared samples’ elements were confirmed to be present based on their chemical composition by the EDX analysis. The Kubelka-Munk function was used to calculate the optical band-gap energy E_g based on the near-infrared (NIR) and visible (VIS) reflectance spectra, which are dependent on Mn dopant ion concentration. The VSM findings demonstrate that the characteristics of the samples transformed gradually from antiferromagnetic to ferromagnetic behavior with increasing Mn content. The dielectric results exhibit that the doping of Mn ions decreases the dielectric constant and dielectric loss and increases the resistivity. The physical properties of Mn_xZn_1−xLa_0.1Fe_1.9O₄ nanoparticles, such as their low power losses, coercivity, high resistivity, permittivity, and saturation magnetization, make them suitable for many applications, from biomedical to electronic devices.