Influence of synthetic temperature on structural and magnetic properties of Dy substituted Ni nanoferrite

Dy substituted Ni ferrite nanoparticles with composition NiFe1.95Dy0.05O4 were synthesized by using the citric acid sol–gel auto combustion method. The samples were sintered at temperatures of 400°C, 700°C, and 900°C. The X-ray diffraction measurements clearly showed the formation of a cubic spinel structure along with a small orthoferrite phase for all the sintered samples. The crystallite size increases from 17.79 to 39.36 nm while the grain size increases from 50.70 nm to 83.05 nm. The lattice parameter and lattice volume decrease with increasing sintering temperature was observed. The Spinel ferrite structure of prepared samples has been confirmed from FTIR spectra. With increasing sintering temperature saturation magnetization increases from 25.80 emu/gm to 49.48 emu/gm while the coercivity value decreases from 207.95 Oe to 165.43 Oe. Increasing saturation magnetization and decreasing coercivity values with increasing sintering temperature make the synthesized nanoparticles suitable for high-density data storage devices.