Effect of sintering temperature on the structural, morphological, and the magnetic properties of Ni0.25Cu0.55 Zn0.20 Fe2O4 nano ferrite

Abstract

Ni0.25Cu0.55Zn0.20Fe2O4 nano ferrite was synthesized using sonochemical method. The as-synthesized nano ferrite was sintered at different (200 °C, 400 °C, 600 °C, and 800 °C) sintering temperature and characterized using various characterization techniques. Identification of the phase was studied using X-ray diffraction. Rietveld refinement confirmed a single-phase cubic spinel structure with Fd3m space group. Average crystallite size and micro strain were estimated using Williamson-Hall plot. FTIR reveals that with the increase in the sintering temperature there is shift in the tetrahedral and octahedral band position. FESEM and TEM images revealed the nanocrystals exhibit irregular shapes which transformed into cubic and hexagonal morphology with the increase in the sintering temperature. The EDAX was employed to confirm the elemental composition of the synthesized Ni0.25Cu0.55 Zn0.20Fe2O4 nano ferrite. The optical behaviour of Ni0.25Cu0.55 Zn0.20Fe2O4 nano ferrite sintered at different temperature was characterized by UV-Diffuse reflectance studies (UV-DRS). Formation of spinel ferrite and distribution of cations at different sintering temperature in Ni0.25Cu0.55 Zn0.20Fe2O4 nano ferrite were determined using Raman spectroscopy. Saturation magnetization (Ms), remanence (Mr), coercivity (Hc), squareness ratio (Mr/Ms), magnetic moment (nB), and anisotropy constant (K) increases with the increase in temperature (200 °C, 400 °C and 600 °C) except 800 °C. Zero field cooling (ZFC), field cooling (FC), and blocking temperature (Tb) were also measured. The blocking temperature (Tb) indicate that the Ni0.25Cu0.55 Zn0.20Fe2O4 nano ferrite exhibit superparamagnetic behaviour, making them suitable for biomedical applications.