Raman and Mössbauer spectroscopic studies of tungsten doped Ni–Zn nano ferrite

In this study, tungsten substituted Ni-Zn nano ferrites of the composition Ni_0.5Zn_0.5W_xFe_2−xO₄ with x = 0.0, 0.2, 0.4 have been synthesized by a co-precipitation method. The prepared samples were pre-sintered at 850 °C and then annealed at 1000 °C for 3 h each. The structural, morphological, optical and magnetic properties of these samples were studied by using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (RS) and Mössbauer spectroscopy (MS). XRD revealed the formation of spinel single-phase structure with an average crystallite size of 53–60 nm. Fourier transform infrared spectroscopy show two prominent peaks primarily due to the tetrahedral and octahedral stretching vibrations in the range of 400–600 cm⁻¹. Raman spectra indicate first order three Raman active modes; (A1 g + Eg + T2 g) at around 688, 475 and 326 cm⁻¹. Mössbauer spectroscopy reveals that substitution of W³⁺ for Fe³⁺ cation results in reduction of total magnetic moment and consequently the net magnetization.