Tunable cationic distribution and structure-related magnetic and optical properties by Cr3+ substitution for Zn2+ in nanocrystalline Ni-Zn ferrites

We report a microwave-combustion synthesis and structure-related physical properties of Ni0.4Zn0.6?xCrxFe2O4 (0.0 ? x 0.6) nanocrystals in study effects by substitution among cations with different oxidation states, Cr3+ for Zn2+. High-quality an average particle size 26–33 nm crystallite ranged 23–32 are revealed transmission electron microscopy (TEM) X-ray diffraction (XRD). Structural cationic redistribution studied the XRD Rietveld analysis implying preferences Zn2+ ions to occupy tetrahedral octahedral sites, respectively. Further characterization characteristic IR absorption bands, ionic valence chemical compositions morphology have been performed employing Fourier transform infrared (FT-IR), photoelectron spectroscopy (XPS) dispersive (SEM-EDX). XPS indicates partial reduction Fe3+ Fe2+ further confirms estimated distribution. UV–Vis absorbance measurements indicated gradual decrease optical energy gap which implies emergence sub-band-gap levels Cr substitution. The magnetic were investigated magnetization showing highly soft behavior. values trend observed moment consistent theoretically calculated based on distributions from XPS. Ni-Zn-Cr spinel nanoferrites properties, up 106 emu/g coercivity down 70 Oe, tunable introduced high-frequency power applications.