High-temperature microwave absorption of SrZrO₃-based coatings: Mechanisms and enhanced absorption by high-impedance surface

The development and optimization of high-temperature microwave-absorbing coatings are crucial for enhancing the performance and survivability of next-generation weapons and equipment. In this work, we prepared microwave-absorbing coatings consisting of 40wt%Sm_0.5Sr_0.5Co_1-xMn_xO₃ and 60wt%SrZrO₃. The loss mechanisms of the coatings were systematically analyzed at various temperatures. It revealed a transition from polarization loss dominance at temperatures below 400 °C to conductivity loss at elevated temperatures, driven by changes in material conductivity and relaxation time. Additionally, simulations incorporating a high-impedance surface showed that a 1.0 mm thick coating achieved an absorption band of less than −10 dB across the X-band at 900 °C, which significantly enhanced microwave absorption capability and reduced the coating thickness. These findings offer critical insights into the design and application of high-temperature microwave-absorbing materials, paving the way for more effective solutions in extreme environments.