Investigation on the synthesis, characterization, and optimization of ternary BaLa_0.4Ce_0.1Fe_11.5O₁₉/ATP/PANI composites as microwave absorption material

In this work, La-Ce-doped hexagonal barium ferrite nanoparticles BaLa_0.4Ce_0.1Fe_11.5O₁₉ were prepared by sol–gel self-propagation method. Based on the influence of material structure and impedance matching on microwave absorption properties, bar-shaped attapulgite (ATP) and highly conductive polyaniline (PANI) were introduced, and BaLa_0.4Ce_0.1Fe_11.5O₁₉/attapulgite/polyaniline (BaLa_0.4Ce_0.1Fe_11.5O₁₉/ATP/PANI) ternary composites were prepared by one-step in situ polymerization. The effects of the mass ratio of BaLa_0.4Ce_0.1Fe_11.5O₁₉ and ATP, the content of BaLa_0.4Ce_0.1Fe_11.5O₁₉ and ATP, polymerization time, and polymerization temperature on the microwave absorption properties have been investigated. The phase composition, micromorphology, absorption properties, and microwave absorption mechanism of the materials were analyzed. The results show that the ternary composite has excellent microwave absorption properties and may become one of the most promising absorption materials. After optimization of the preparation process, when the mass ratio of BaLa_0.4Ce_0.1Fe_11.5O₁₉ and ATP is 93:7, the content of BaLa_0.4Ce_0.1Fe_11.5O₁₉ and ATP is 20 wt%, the polymerization time is 8 h, and the polymerization temperature is 0 °C, BaLa_0.4Ce_0.1Fe_11.5O₁₉/attapulgite/polyaniline(BaLa_0.4Ce_0.1Fe_11.5O₁₉/ATP/PANI) ternary composite has unparalleled microwave absorption performance, the minimum reflection loss can reach − 46.40 dB at 16.2 GHz with a thickness of only 1.6 mm, and the absorption bandwidth with reflection loss below − 10 dB is up to 4.1 GHz (13.9–18 GHz).