This study aims to investigate the microwave absorption characteristics of Y2.5La0.5Fe5O12 and Ba0.9Sr0.1Fe2O4 composite materials with variations in sintering temperature. This study uses yttrium iron garnet or YIG (Y3Fe5O12) material substituted with La3+ elements and Barium Monoferrite (BaFe2O4) substituted with Sr3+ elements. The synthesis of composite compounds was carried out using the so…