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<p>Infrared emissivity and microwave absorption performance are important properties of high-temperature microwave absorption material. High infrared emissivity helps to increase the radiative heat dissipation effect of the coating, thus reducing the temperature and thermal mismatch stress of the coating. In this study, microwave absorption material with high emissivity and wide microwave absorption bandwidth were obtained through Ti doping. The results show that Ti doping, without changing the structure of LaMnO<sub>3</sub> perovskite, reduces the bandwidth of LaMnO<sub>3</sub> perovskite due to the 3d orbitals of Ti, thereby affecting its electron transport and infrared optical properties. When the doping amount is 0.3, the infrared emissivity of LaMn<sub>0.7</sub>Ti<sub>0.3</sub>O<sub>3</sub> was improved from 0.74 to 0.78. Furthermore, UV–Vis-NIR diffuse-reflectance measurements converted via the Kubelka–Munk function and analyzed by Tauc plots reveal a red-shifted absorption edge and a reduced optical band gap from 1.93&#xa0;eV to 0.95&#xa0;eV, which further indicate the reduction of bandgap. Meanwhile, the doping of Ti also optimizes the microwave absorption performance of the LaMnO<sub>3</sub>. Within the X-band (8.2–12.4&#xa0;GHz) test range, when the doping amount is 0.1 and the thickness is 2.6&#xa0;mm, the minimum reflection loss (RL<sub>min</sub>) is -25.74&#xa0;dB, and when the doping amount is 0.2 and the thickness is 3.0&#xa0;mm, the maximum effective absorption bandwidth (EAB) is 3.09&#xa0;GHz. The superior absorption arises from lattice-distortion-induced oxygen vacancies that enhance charge transport and dielectric loss, together with improved impedance-matching. A co-regulation strategy involving B-site Ti substitution is introduced to concurrently enhance infrared emissivity and fine-tune dielectric loss, establishing a broadly applicable design pathway for high-temperature, low-signature microwave-absorbing coatings.</p>

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Enhancing the infrared emitting ability and microwave absorption properties of LaMn1-xTixO3

  • 期刊论文

  • 发表日期：

    2025年9月15日

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  • Chuangdong Zhang,
  • Yingying Zhou,
  • Quanye Zhao,
  • Zhaowen Ren,
  • Yikun Yang,
  • Enyuan Zhen,
  • Haonan Du,
  • Chenyu Zhu

摘要

Infrared emissivity and microwave absorption performance are important properties of high-temperature microwave absorption material. High infrared emissivity helps to increase the radiative heat dissipation effect of the coating, thus reducing the temperature and thermal mismatch stress of the coating. In this study, microwave absorption material with high emissivity and wide microwave absorption bandwidth were obtained through Ti doping. The results show that Ti doping, without changing the structure of LaMnO3 perovskite, reduces the bandwidth of LaMnO3 perovskite due to the 3d orbitals of Ti, thereby affecting its electron transport and infrared optical properties. When the doping amount is 0.3, the infrared emissivity of LaMn0.7Ti0.3O3 was improved from 0.74 to 0.78. Furthermore, UV–Vis-NIR diffuse-reflectance measurements converted via the Kubelka–Munk function and analyzed by Tauc plots reveal a red-shifted absorption edge and a reduced optical band gap from 1.93 eV to 0.95 eV, which further indicate the reduction of bandgap. Meanwhile, the doping of Ti also optimizes the microwave absorption performance of the LaMnO3. Within the X-band (8.2–12.4 GHz) test range, when the doping amount is 0.1 and the thickness is 2.6 mm, the minimum reflection loss (RLmin) is -25.74 dB, and when the doping amount is 0.2 and the thickness is 3.0 mm, the maximum effective absorption bandwidth (EAB) is 3.09 GHz. The superior absorption arises from lattice-distortion-induced oxygen vacancies that enhance charge transport and dielectric loss, together with improved impedance-matching. A co-regulation strategy involving B-site Ti substitution is introduced to concurrently enhance infrared emissivity and fine-tune dielectric loss, establishing a broadly applicable design pathway for high-temperature, low-signature microwave-absorbing coatings.