Composition dependence of the elastic moduli of mixed lithium–cadmium ferrites

Mixed Li–Cd ferrites having the chemical formula Li0.5−x/2CdxFe2.5−x/2O4 (where x=0.2, 0.4, 0.6, 0.8, and 1.0) are prepared by the well-known double sintering ceramic technique. From x-ray diffraction studies lattice parameters are calculated and their variation with composition is explained on the basis of the tetrahedral ionic radius. The bulk density of the specimens are determined by the hydrostatic method and the percentage porosity was calculated. The ultrasonic compressional (V1) and shear (Vs) velocities of mixed Li–Cd ferrites are measured at room temperature by the ultrasonic pulse transmission technique. The values of Young’s modulus, the rigidity modulus, Debye temperatures, and average sound velocities are calculated from the experimental values of V1 and Vs. The elastic moduli have been corrected to zero porosity. The variation of elastic moduli with composition is interpreted in terms of binding forces between the atoms.