Synthesis, structural and magnetic properties of cadmium substituted Li-ferrite

We present study of Li0.5-x/2CdxFe2.5-x/2O4 (thermally treated at 450 °C for 3 hours) nano crystalline ferrites, synthesized by sol-gel auto-combustion method. X-ray diffraction (XRD), magnetic measurements were used to probe the structural, magnetic properties. Results show that successive Cd2+ addition leads to: i) formation of nano-crystalline phase (Williamson-Hall grain diameter DW-H range between 16.0 nm – 63.6 nm). Slight presence of α-Fe2O3 phase was also observed, ii) changes in experimental lattice parameter aexp (range between 0.8321 nm – 0.8373 nm), obtained cell volume (V), specific surface area (S), X-ray density (ρXRD), are ascribed to the difference in ionic radii of Fe3+, Cd2+, Li1+ ions; and Cd2+ ions migrate predominantly to A-site (thus pushing Fe3+ ions on B site) leading to increased distortion in the lattice displayed by increase of oxygen parameter (u) from 0.3797 to 0.3849, iii) migration of cations leads to changes in saturation magnetization Ms (varies between 52.7 Am2/kg – 61.7 Am2/kg), whereas coercivity Hc varies between 111.09 Oe−150.04 Oe, iv) formation of softer magnetic material with minimum losses of 1.61 J/kg, v) linear variation of Hc with grain diameter, reveals that the studied samples lie in the region with overlap between single or multi-domain region. Current study clearly shows strong correlation between structural, magnetic properties.