Improved magnetic and electrical properties of Zn substituted nanocrystalline MgFe2O4 ferrite

•Nanocrystalline Mg1−xZnxFe2O4 mixed ferrites were synthesized using a solvent-free combustion reaction method.•Effects of Zn substitution on the structural, magnetic, and electrical properties of MgFe2O4 were investigated.•The highest value of magnetization (31.17 emu/g) was obtained for the superparamagnetic Mg0.6Zn0.4Fe2O4 sample.•The lowest value of electrical conductivity (2.14 × 10−10 S/cm) achieved for the Mg0.4Zn0.6Fe2O4 sample. The structural, magnetic, and electrical properties of Mg1−xZnxFe2O4 (0.0 ≤ x ≤ 0.8) nanoferrites synthesized using a solvent-free combustion route have been investigated. The X-ray diffraction study (XRD) reveals the single-phase nature of ferrites and the size of the crystallites is increased from 10.4 nm to 16.5 nm. Raman spectra show that the position of the vibrational modes varies with Zn. Transmission electron microscope (TEM) analysis shows that the particle size increases from 9.92 nm to 12.59 nm. An enhancement in magnetization is observed up to x = 0.4 at 300 K which decreases thereafter. Further, the samples exhibiting superparamagnetism and the blocking temperature decrease from 138.96 K to 65.27 K. The conductivity at 303 K decreases up to x = 0.6 whereas the activation energy enhances from 0.45 eV to 0.60 eV. The highest value of resistance is obtained for Mg0.4Zn0.6Fe2O4 sample. The results suggest that the prepared samples are promising candidates for biomedical and high-frequency device applications, respectively.