Synthesis, characterization and antistructure modeling of Ni nano ferrite.

We report the role played by cation distribution in determining magnetic properties by comparing dry gel, thermally annealed Ni ferrite prepared by sol-gel auto-combustion technique. X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Mössbauer spectroscopy were used to characterize the samples. Both XRD and Mössbauer measurements validate the formation of spinel phase with grain diameter 39.13−45.53 nm. First time antistructural modeling for Ni ferrite is reported to get information on active surface centers. Decrease of Debye temperature <italic>θ</italic><italic>_D</italic> in annealed sample shows enhancement of lattice vibrations. With thermal annealing experimental and Néel magnetic moment (<italic>n</italic><italic>_B^e</italic>, <italic>n</italic><italic>_B^N</italic>) increases, suggesting migration of Ni²⁺ from B to A site with concurrent migration of Fe³⁺ from A to B site (non-equilibrium cationic distribution), affecting magnetic properties. [ABSTRACT FROM AUTHOR]