Physico-chemical studies on synthesis, characterization, and magnetic properties of Li–Ca–Zn nanoferrites

The synthesis of Li0.25Ca0.5–XZnXFe2.25O4 (LCZ) spinel nanoferrites by the solution combustion method using oxalyl-dihydrazide as a fuel leads to the formation of fine nanoparticles. Structural studies such as X-ray diffraction and transmission electron microscope confirm the formation of single phase spinel with particle size in the range 26–43 nm while Mössbauer data under the shadow of magnetic studies attribute to the superparamagnetic nature of the ferrites obtained, resulting from the transition of ferrimagnetic to superparamagnetic phase. In addition, the magnetic studies reveal an initial increase in the saturation magnetization (MS) from 33.5 emu/g for X = 0–41.4 emu/g (X = 0.3) followed by a gradual decrease to 32.8 emu/g (X = 0.5) as the concentration of zinc increases while Curie temperature lies in the range 312–527 °C for the same series. Keeping in view the various properties of the nanoferrites formed, variation of dielectric constant has also been carried out with both frequency (20 Hz–1 MHz) and temperature (up to 500 °C). We believe that the synthesized LCZ nanoferrites can be suitable for their application in nanomagnetic and nanoelectronic devices for drug delivery and bioencapsulating systems.