Direct and facile synthesis of Li–Sr–Zn ferrites via low temperature solution combustion route

Li–Sr–Zn nanoferrites i.e. Li0.25Sr0.5–xZnxFe2.25O4, where ‘x’ varies from 0–0.5, have been synthesized using a low temperature solution combustion method which proves to be an efficient and economical technique for synthesizing these type of nanoferrites. The as-synthesized nanoferrites have cubic spinel structure as characterized by X-ray powder diffraction. Powder XRD and TEM (Transmission Electron Microscopy) characterization also evidence that the crystallite and particle size are in close agreement to each other. Mössbauer spectroscopy studies demonstrate that there is a gradual transition from ferrimagnetic to superparamagnetic character, which is also supported by the saturation magnetization and coercivity values. At room temperature, the nanoferrites were found to be superparamagnetic with negligible coercivities approaching towards zero while saturation magnetization values were found to be in the range 6.87–30.10 emu g−1. The frequency dependent dielectric constant and loss values are in accordance with Koop׳s model. These nanoferrites show great potential in high density recordings, magnetic nanodevices and biomagnetic applications.