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

We present study of Li 0.5-x/2 Cd x Fe 2.5-x/2 O 4 (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 Cd 2+ addition leads to: i) formation of nano-crystalline phase (Williamson-Hall grain diameter D W-H range between 16.0 nm-63.6 nm). Slight presence of -Fe 2 O 3 phase was also observed, ii) changes in experimental lattice parameter a exp (range between 0.8321 nm-0.8373 nm), obtained cell volume (V), specific surface area (S), X-ray density ( XRD), are ascribed to the difference in ionic radii of Fe 3+ , Cd 2+ , Li 1+ ions; and Cd 2+ ions migrate predominantly to A-site (thus pushing Fe 3+ 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 M s (varies between 52.7 Am 2 /kg-61.7 Am 2 /kg), whereas coercivity H c 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 H c 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.