Fe/Sr ratio and calcination temperature effects on processing of nanostructured strontium hexaferrite thin films by a sol–gel method

Nanostructured single-phase strontium hexaferrite, SrFe12O19 (SrM), thin films have been synthesized successfully for the first time on silicon substrates using a spin-coating sol–gel process. The precursor solution was prepared from metal nitrates, citric acid, and ethylene glycol. The thin films with various Fe/Sr molar ratios of 8–12 were heat treated at different temperatures from 700 to 900 °C. The composition, microstructure, and magnetic properties of the SrM thin films were also characterized. The results showed that the optimum molar ratio for Fe/Sr was 10, at which the lowest calcination temperature for obtaining the single-phase strontium hexaferrite thin films was 800 °C. The crystallite size of the resultant thin films was below 50 nm.