Investigation of structural, morphological and magnetic properties of nanostructured strontium hexaferrite through co-precipitation technique: Impacts of annealing temperature and Fe/Sr ratio

Abstract

M-type strontium hexaferrite (SrM) were successfully synthesized from Sr2+ and Fe3+ precursor salt through co-precipitation technique. Different higher sintering temperatures (800–1000 °C) were used to get the desired SrM with variation of Fe3+/Sr2+ mole ratio as well. The characterization of SrM and its properties were investigated using modern instrumental techniques viz. X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer, Scanning Electron Microscopy, Vibrating Sample Magnetometer, UV–Visible NIR Spectrometer, Impedance Analyzer and Thermal Conductivity Meter. The phase of the synthesized SrM were confirmed by comparing the XRD patterns with the standard ICDD data and Reitvelt Refinement for the SrM having Fe3+/Sr2+ ratio 10 and SrM with distinct annealing temperature were performed. The structural parameters, particle size (75 nm–318 nm) and shape of the as prepared samples were changed with calcination temperature as well as mole ratio. The saturation magnetization (73.77–24.27 emu/g), coercivity (3732.28–642.10 Oe) and remanant magnetization (39.15–8.86 emu/g) were varied with calcination temperature and composition. The dielectric properties, optical properties and thermophysical properties were measured for the SrM keeping Fe3+/Sr2+ ratio 10 calcined at 1000 °C. The synthesized SrM can be applied in magnetic recording media and as photocatalyst due to its low coercivity (2764.48 Oe), high saturation magnetization (73.77 emu/g) and low band gap energy (Eg-2.04 eV) respectively.