Investigation of structural and magnetic properties of NiO/BaFe12O19/Ni0.5Zn0.5Fe2O4 nanocomposites.

Pure NiO, BaFe₁₂O₁₉, and Ni_0.5Zn_0.5Fe₂O₄ nanoparticles were synthesized by the co-precipitation method. Four ternary (1 − x–y)NiO/xNi_0.5Zn_0.5Fe₂O₄/yBaFe₁₂O₁₉ (x and y between 0 and 1) nanocomposites (NCs) were prepared by the wet ball milling technique, then calcined at 950 °C for 4 h. The X-ray powder diffraction (XRD) validated the production of pure NiO and Ni_0.5Zn_0.5Fe₂O₄ without impurities, while BaFe₁₂O₁₉ was produced with the α-Fe₂O₃ additional phase. When compared to the initial weight percentages, the Rietveld refinement technique revealed different weight percentages for the three phases. The transmission electron microscope (TEM) and the selected area electron diffraction (SAED) investigated the morphology and the microstructure of the samples, respectively. X-ray photoelectron spectroscopy (XPS) showed that nanocomposites were successfully formed from the examination of the elements constituting the nanocomposites (Ba²⁺, Ni²⁺, Ni³⁺, Zn²⁺, Fe³⁺and O²⁻). The vibrating sample magnetometer (VSM) measurements identified the effect of the weight percentage of each phase in the nanocomposite on the magnetic parameters. The switching field distribution (SFD) curves indicated significant exchange coupling interactions in the samples that include a small weight percentage of BaFe₁₂O₁₉. Exchange and dipolar interactions were both recognized in Henkel plots of all samples, although exchange coupling predominated. Four laws of approach to saturation (LAS) were applied to the samples and showed magnetization dependency on H⁻¹ and H^−1/2 rather than the summation of H⁻¹, H⁻², and H for almost all samples. [ABSTRACT FROM AUTHOR]