Effect of Annealing Temprature on Structural, Magnetic and Elastic Properties of Magnesium Nickel Ferrite Nanoparticles

Abstract

The aqueous synthesis of MgNi ferrite nanoparticles synthesized is demonstrated using sol-gel method using nitrates of Mg, Ni and iron as precursors and citric acid as fuel in a water based synthesis. The ferrites were annealed at 900◦C and 1100◦C temperatures. To know the structural, morphological, elastic and magnetic properties, the nanoparticles so prepared were characterized using X-ray diffraction technique (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), FTIR spectroscopy and Raman spectroscopy. The results of XRD, FTIR and Raman spectroscopy patterns are indicative of formation of ferrite nanoparticles and the structural studies confirm the inverse spinel structure with crystallite size 35-61 nm and 66-94 nm for ferrites annealed at 900◦C and 1100◦C respectively. The formation of inverse spinel ferrite structure is confirmed by absorption bands corresponds to vibration of tetrahedral site-A and by absorption bands corresponds to the octahedral site-B. Crystallite size calculations were carried out using Williamson-Hall plot. Rietveld refinement was applied to assure the crystal structure and allied parameters. The magnetic analysis of the prepared samples indicates that the nanoparticles exhibited superparamagnetic behaviour having high magnetic saturation (MS) and negligible coercivity (HC). The estimation of elastic properties through absorption bands reveal improvement when the same precursor is annealed at higher temperatures i.e. 1100◦C. Uniform deformation model (UDM), uniform stress deformation Stress (USDM) and uniform energy deformation model (UEDM) were first time successfully applied on the MgNi ferrite spinel nanoparticles SNPs. The elastic properties were studied estimating the elastic constants and compliances and applying them for three deformations. A comparative study for two sets of samples confirms the rise in stability factor annealed at higher temperature.