Effect of nickel substitution on structural, infrared and elastic properties of lithium ferrite

596-608The structural and elastic properties of Li₀․₅ (1-x)NixFe₂․₅-₀․₅xO₄ (x = 0.0-1.0) spinel ferrite system have been studied by means of X-ray diffraction and infrared spectroscopic measurements at 300K. The X-ray diffraction data has been used to determine the lattice constant, X-ray density, distributions of cations among the tetrahedral and octahedral sites of spinel lattice, anion parameters, site radii, ionic radii, bond angle and bond length. The nature and change in the position of IR bands have been explained on the basis of cations involved in the system. The force constants have been used to calculate elastic moduli like bulk modulus, rigidity modulus, Young’s modulus, Poisson’s ratio, Debye temperature and corrected to zero porosity. The observed variation of elastic constants with nickel substitution has been explained on the basis of strength of interatomic bonding. The applicability of heterogeneous metal mixture rule for estimating elastic constants has been tested. The Debye temperature obtained from elastic constant data is higher than that of the X-ray diffraction analysis, mainly due to existence of peaks in the vibrational spectra at lower frequencies