Estimation and association of structural, elastic and magnetic properties of magnesium-nickel-ferrite nanoparticles annealed at different temperatures

[Display omitted] •Mg Ni Ferrites synthesized via citrate gel method without any impurity phase.•Thermal fluctuations caused elastic anisotropy (acquittal of precursor gases).•Magnetic anisotropy found decreased at higher annealing temperature.•Magnetic susceptibility increased with annealing temperature and linked to SFD.•Elastic properties increase on increasing annealing temperature. The Mg-Ni-Ferrite nanoparticles were prepared by sol–gel method using nitrates of magnesium, nickel, iron and citric acid as fuel in a hydrated synthesis. The precursor was annealed at temperatures 900°C and 1100°C. The structural studies confirm the inverse-spinel structure with crystallite size 30–70 nm. Morphological analysis signifies the formation of nanocrystalline Mg-Ni-Ferrites and suggests that the nanoparticles exhibited super-paramagnetic behaviour. Raman and FTIR spectra claim the formation of spinel ferrite structures. The estimation of elastic properties, elastic constants and compliances were performed through absorption bands and by two methods and applied in three deformations “Uniform, (UDM), Stress (USDM), Energy (UEDM) Deformation”, models successfully for the first time and reveals that the values improve when the same precursor is annealed at higher temperatures. Elastic properties predict the stability of nanoparticles and show improvement in structural, elastic properties and switching field distribution (SFD) with increasing annealing temperature.