Impact of Copper Substitution on the Structural Refinement, Magnetic Behaviour, and Dielectric Response of Ni–Zn Spinel Ferrites

• Published in: Physics of the solid state Vol. 67; no. 2; pp. 148 - 163
• Main Authors: Ingle, Arti A., Fulari, Akash V., Borade, Rameshwar B., Kadam, S.B., Mote, V. D., Kadam, A. B., Shirsath, Sagar E., Kadam, R. H.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.02.2025; Springer Nature B.V
• Subjects: Copper; Crystallites; Differential thermal analysis; Field emission microscopy; Fourier transforms; Grain size; High resolution electron microscopy; Magnetic properties; Magnetic saturation; Microscopy; Physics; Physics and Astronomy; Sol-gel processes; Solid State Physics; Spinel; Substitutes; Thermal decomposition; saturation magnetization; Cu-substituted Ni–Zn ferrite; structural analysis; cation distribution; dielectric constant; rietveld refinement
• ISSN: 1063-7834; 1090-6460
• DOI: 10.1134/S1063783424602078

Ni 0.5 Zn 0.5− x Cu x Fe 2 O 4 ( x   =  0, 0.05, 0.1, 0.15, 0.2, 0.25) spinel ferrite nanoparticles were synthesized via the sol-gel auto-combustion method and sintered at 700°C for 5 h. Thermogravimetric and differential thermal analysis (TG-DTA) revealed the thermal decomposition behaviour. Single phase ferrite with Fd ‑3 m space group was confirmed by the Rietveld refinement of X-ray diffraction data. The distribution of cation among octahedral B and tetrahedral A-site was estimated by the computational method. With increasing copper substitution, the lattice parameter decreased while X-ray density increased. Crystallite sizes ranged from 22 to 24 nm, consistent with the Williamson–Hall method, and strain decreased. Fourier-transform infrared (FTIR) spectroscopy confirmed the spinel structure. High-resolution transmission electron microscopy (HR-TEM) and field emission scanning electron microscopy (FE-SEM) showed grain sizes between 70 and 130 nm. Energy dispersive X-ray (EDAX) analysis confirmed chemical purity. Magnetic studies showed an increase in saturation magnetization and coercivity (42 to 57 Oe) with copper substitution, while dielectric behaviour followed the Maxwell–Wagner model.