Enhancement of the magnetic and optical properties of Ni0.5Zn0.5Fe2O4 nanoparticles by ruthenium doping

The characterization of Nanosized Ni 0.5 Zn 0.5 Ru x Fe 2− x O 4 (0.00 ≤ x ≤ 0.015), prepared by the wet chemical coprecipitation method, is reported in the current investigation. X-ray powder diffraction (XRD) analysis has confirmed the formation of a single phased spinel cubic structure. While transmission electron microscopy (TEM) studies have shown an increase in the particle size for high content of Ru 3+ doping. The elemental composition of all samples was investigated using energy dispersive x-ray (EDX) measurements. The results showed a reciprocal relation between the Fe 3+ and Ru 3+ contents, suggesting the successful substitution of Ru 3+ in Fe 3+ sites. UV–Vis spectroscopy studies, via Urbach energy analysis, proposed a perturbation in the band structure of Ni 0.5 Zn 0.5 Fe 2 O 4 induced by Ru 3+ substitution, affecting both the direct and indirect bandgap energies. Excitation wavelength-dependent photoluminescence (PL) studies, presented for the first time, have shown a strong dependence of the emission spectra on both the excitation wavelength and Ru 3+ doping. The PL analysis suggests the utilization of Ni 0.5 Zn 0.5 Ru x Fe 2− x O 4 as a candidate for photocatalytic applications. Furthermore, VSM studies, have shown a transition from superparamagnetic to soft ferromagnetic for Ru 3+ doped samples. The saturation magnetization, coercivity, and effective anisotropy were enhanced as a result of Ru 3+ doping. Finally, photocatalysis experiments have shown an enhancement of the degradation rate of nitrobenzene for the sample with x = 0.0125 with the ability of magnetic recycling, in agreement with the PL and VSM studies.