Characterization of Microwave Absorber Material Based on Strontium Samarium Ferrite Produced by Hybrid Sol-Gel Method

Several studies have been carried out to attain microwave absorber materials to reduce the level of exposure of electromagnetic waves that can damage various electronic devices and disrupt human health. This study aims to determine the characterization of microwave absorber material of strontium ferrite with samarium doping and made by using the hybrid sol-gel method, which is a combination of sol-gel and solid-state reaction. The initial stage was to process Fe3O4 into Fe(NO3)3 and then mix it with Sr(NO3)2 and Sm2O3. The mixture was made into a sol and then heated into a gel. After that, the sample was calcined to become powder. Then the sample powder is compacted and sintered at a temperature of 1100 °C. The XRD, VSM, and VNA characterization results show that the addition of samarium doping affects changes in microstructure, particle size, and magnetic properties. The final results show the formation of four phases, namely SrFe12O19 (hexagonal), Sr2FeO4 (tetragonal), FeSmO3 (orthorhombic) and Sm2Fe17 (rhombohedral) which have particle sizes of 21–23 nm and susceptibility values of (3.5–7.3) × 10−6 m3/kg. Strontium ferrite samples with 0.15% mol of samarium doping concentration have the best microwave absorption ability of −19.523 dB at a frequency of 10.74 GHz.