Effects of Particle Size on Electromagnetic and Microwave Absorption Properties of L a _0.7 S r _0.3 M n O _3±δ ‐Epoxy Composite

L a _0.7 S r _0.3 M n O _3±δ powders were fabricated by solid‐state reaction method at 1473 K for 4 h. The precursors were prepared by ball‐milling raw materials for 3, 6, 9, and 12 h, respectively. The crystal structures, particle size, and morphologies of precursors and prepared L a _0.7 S r _0.3 M n O _3±δ were characterized by XRD , laser particle size analyzer and SEM , respectively. It is found that L a _0.7 S r _0.3 M n O _3±δ possessed large particle size by ball‐milling raw materials for a long time. Results indicated that L a _0.7 S r _0.3 M n O _3±δ , synthesized by ball‐milling raw materials for 3 h, exhibited the optimal microwave absorption properties. The maximum reflection loss was −28.8 dB, and the −6 dB absorption bandwidth was 5.80 GHz.