Structural, optical and magnetic studies of Ce doped NiFe2O4 nanoparticles

• Structural, magnetic and optical properties NiCexFe2−xO4 nanoparticles are studied.
• XRD shows that only up to x=0.08, the samples are in pure phase.
• Optical band gap increases while magnetic moment decreases after doping with Ce.
• VSM shows random variation of magnetic moment with Ce concentration.
• Mössbauer spectra show ferromagnetic nature of all samples.

Structural, optical and magnetic properties of NiCexFe2−xO4 (x=0.0–0.10) nanoparticles prepared by the chemical route, have been studied. All the samples exhibit pure spinel phase except that with x=0.10. Crystallite size decreases gradually from 57 to 17 nm as the Ce concentration increases from 0 to 0.10. Fourier transform infrared spectroscopy shows that in comparison to pure nickel ferrite, the bands corresponding to Fe–O vibration are shifted towards higher wave number after doping with Ce. The Mössbauer spectra for all the compositions show the presence of two sextets at room temperature showing the ferrimagnetic character of the samples. Magnetic hysteresis curves show that the saturation magnetisation changes from ∼41.8 emu/g for pure nickel ferrite to ∼31.6 emu/g after doping with Ce=0.10. However, the variation of magnetic moment with Ce concentration is irregular. The cation distribution in the samples shows the mixed spinel structure.