Microstructural and Mössbauer properties of low temperature synthesized Ni-Cd-Al ferrite nanoparticles

We report the influence of Al3+ doping on the microstructural and Mössbauer properties of ferrite nanoparticles of basic composition Ni0.2Cd0.3Fe2.5 - xAlxO4 (0.0 ≤ x ≤ 0.5) prepared through simple sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray, transmission electron microscopy (TEM), Fourier transformation infrared (FTIR), and Mössbauer spectroscopy techniques were used to investigate the structural, chemical, and Mössbauer properties of the grown nanoparticles. XRD results confirm that all the samples are single-phase cubic spinel in structure excluding the presence of any secondary phase corresponding to any structure. SEM micrographs show the synthesized nanoparticles are agglomerated but spherical in shape. The average crystallite size of the grown nanoparticles was calculated through Scherrer formula and confirmed by TEM and was found between 2 and 8 nm (± 1). FTIR results show the presence of two vibrational bands corresponding to tetrahedral and octahedral sites. Mössbauer spectroscopy shows that all the samples exhibit superparamagnetism, and the quadrupole interaction increases with the substitution of Al3+ ions

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

In this study, tungsten substituted Ni-Zn nano ferrites of the composition Ni0.5Zn0.5WxFe2−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